The genus Acentropelma Pocock, 1901 is redefined and the type species, A. spinulosum F.O. Pickard-Cambridge, 1897 is redescribed. Pseudo- schizopelma Smith, 1995 gen.rest. is restored to house Acentropelma macropus (Ausserer, 1875) creating the restored combination Pseudoschizopelma macropus comb.rest. Acentropelma sorkini Smith, 1995 syn.n. is considered a junior synonym of P. macropus based on indistinguishable palpal bulb, tibial apophysis and sper- mathecal morphology. The paratype female of former A. sorkini, originally designated and described by Smith  is found to be an immature Brachypelma Si- mon, 1891 – possibly Brachypelma kahlenbergi Rud- loff, 2008. Additional morphological features for A. gutzkei are included to complement the original de- scription by Reichling , and its placement dis- cussed.
A new species of Umbyquyra Gargiulo, Brescovit & Lucas, 2018, Umbyquyra gurleyi sp. nov., is described from Goiás, Brazil, based on distinctive palpal bulb morphology.
Three new species of the genus Psalmopoeus Pocock, 1895 are described from Central America: P. copanensis sp. nov. from Honduras, P. sandersoni sp. nov. from Belize, and P. petenensis sp. nov. from Guatemala. The taxonomic placement of other species within the Reduncus Group is addressed: P. intermedius Chamberlin, 1940 is redescribed and its type locality discussed, P. reduncus (Karsch, 1880) is redescribed from a lectotype and paralectotype designated herein, P. maya Witt, 1996 is consid- ered a species inquirenda based on the type series being absent from its stated repository, and additional morphological data for P. victori Mendoza, 2014 is detailed to complement the original description. Furthermore, a morphometric methodology for evaluation of female spermathecae is presented and its use in species delineation discussed.
The taxonomic placement of species within the genus Pseudhapalopus
Strand, 1907 is addressed and revised in a modern context
alongside other similar taxa. The genotype Pseudhapalopus
aculeatus Strand, 1907 is proposed as a species inquirenda.
Cymbiapophysa gen. nov. is established to house Cymbiapophysa
velox (Pocock, 1903) comb. nov. and Cymbiapophysa
yimana sp. nov., based on palpal bulb, tibial apophyses, palpal
tibial, and spermathecal morphology. Spinosatibiapalpus gen.
nov. is established to house Spinosatibiapalpus spinulopalpus
Schmidt & Weinmann, 1997 comb. nov., Spinosatibiapalpus
tansleyi sp. nov. and Spinosatibiapalpus trinitatis comb. nov.
based on palpal bulb, tibial apophyses, palpal tibial, and spermathecal
morphology. Pseudhapalopus trinitatis pauciaculeis
(Strand, 1916) is proposed as a junior synonym of Spinosatibiapalpus
trinitatis syn. nov. based on indistinguishable palpal
bulb, tibial apophysis, and palpal tibial morphology. Bumba pulcherrimaklaasi
(Schmidt, 1991) is proposed as a nomen
dubium due to the condition of the holotype and an inadequate
original description. The monotypic species Miaschistopus tetricus
(Simon, 1889) is redescribed with an emended generic diagnosis.
New aspects of palpal bulb morphology are considered
with introduction of novel terminology.
Specimens of the widely distributed ischnocoline species Holothele longipes (L. Koch, 1875) are formally reported from Guyana and Panama for the first time, based on examination of material from the collections of Natural History Museum, London, Oxford University Museum of Natural History and Museo de Invertebrados G. B. Fairchild, Universidad de Panama.
The chaotic taxonomy of the subfamily Ornithoctoninae
Pocock, 1895 is partially addressed, with a focus on redefining
the arboreal genera Lampropelma Simon, 1892, Omothymus
Thorell, 1891, and Phormingochilus Pocock, 1895. Previous
works placing heavy emphasis on unstable taxonomic characters
are addressed and stable taxonomic features presented for the
clear delineation of males of arboreal ornithoctonine genera.
The male of Phormingochilus everetti Pocock, 1895 is described
for the first time. A new species, Omothymus rafni sp. nov.
is described from historical material collected in Sumatra.
Lampropelma violaceopes Abraham, 1924 is transferred to
Omothymus based on comparative leg measurements and
geographical location comb. nov. Lampropelma nigerrimum
arboricola Schmidt & Barensteiner, 2015 is transferred to the
genus Phormingochilus with full species status acknowledged,
giving the new combination Phormingochilus arboricola
comb. nov. Omothymus thorelli Simon, 1901 is considered
a junior synonym of Omothymus schioedtei Thorell, 1891
syn. nov., based on similar morphology and geographical
locations. Phormingochilus carpenteri Smith & Jacobi, 2015
is transferred to the genus Lampropelma based on comparative
leg measurements and geographical location comb. nov.
Phormingochilus kirki Smith & Jacobi, 2015 is considered a
junior synonym of L. carpenteri syn. nov. Phormingochilus
fuchsi Strand, 1906 is transferred to the genus Omothymus based
on comparative leg measurement and geographic distribution
comb. nov. Phormingochilus tigrinus Pocock, 1895 is removed
from synonymy with P. everetti based on the lack of justification
for the synonymy comb. rest. Omothymus dromeus Chamberlin,
1917 is removed from Omothymus and returned to the restored
genus Melognathus comb. rest.
Aphonopelma braunshausenii Tesmoingt, 1996 is regarded as a nomen dubium due to the lack of a deposited holotype, an inadequate description which gives no stable taxonomic features to differentiate it from any other species and the absence of an exact type locality. The instability of some morphological characters which were given weight for species delineation in many earlier works is discussed and illustrated.
The recent rediscovery and examination of the holotype
of Neischnocolus panamanus Petrunkevitch, 1925 and its
comparison with type material of the genera Barropelma
Chamberlin, 1940 and Ami Pérez-Miles, 2008 led us to
establish their generic synonymy. Ami species and the
monotypic Barropelma parvior (Chamberlin & Ivie, 1936)
fit with the diagnostic characters of Neischnocolus, with the
presence of modified type I urticating setae and the singular
spermathecal morphology. B. parvior is considered a junior
synonym of N. panamanus syn. nov. based on genital organ
morphology and geographical location. Ami bladesi Pérez-
Miles, Gabriel & Gallon, 2008 is also considered a junior
synonym of Neischnocolus panamanus syn nov. based on
genital organ morphology and geographical location. As a
consequence, of the synonymies of the genera Barropelma and
Ami with Neischnocolus, seven new combinations are created:
N. amazonica comb. nov., N. armihuarensis comb. nov., N.
caxiuana comb. nov., N. obscurus comb. nov., N. pijaos comb.
nov., N. weinmanni comb. nov. and N. yupanquii comb. nov.
Montenegro et al. (2018) reported the theraphosid spider genus Homoeomma Ausserer, 1871 from Chile and described a new species of this genus with distinctive red and black colouration, naming it Homoeomma chilensis Montenegro & Aguilera, 2018. Soon after, Sherwood et al. (2018) described Homoeomma bicolor also from Chile having the same colouration. In this work, we demonstrate these nominal species to be synonymous and H. chilensis is regarded as the valid senior synonym of H. bicolor following the Article 23 of the Code (Anonymous 1999).
This case represents an instance where two independent scientific teams described the same taxon, in different journals published within a very short period of time of each other, respectively dated October and November of the same year, causing two available binominal names to exist for a single species (Anonymous 2019). Here we resolve this situation through synonymy, discuss an additional morphological character not mentioned in the original description by Montenegro et al. (2018) and note further intraspecific variation that exists for H. chilensis. Potential homonymy in Chilean theraphosid nomenclature is also discussed.
Poecilotheria chaojii Mirza, Sanap & Bhosale, 2014 is proposed as a junior synonym of Poecilotheria tigrinawesseliSmith, 2006 n. syn., based on morphology and distribution. The variability of morphological features given by Mirza, Sanap & Bhosale (2014) is discussed.
A new genus and species of the subfamily Selenocosmiinae Simon, 1892 are described from Sarawak, Borneo: Birupes simoroxigorum gen. et sp. nov. with discussion on the use of palpal bulb, spermathecae and stridulatory organ morphology in selenocosmiine systematics.
A new species of theraphosid spider from
Chile is described: Homoeomma bicolor sp. nov.
The holotype male of Psalmopoeus pulcher Petrunkevitch, 1925 is re-described and the female is described for the first time. Colour ontogeny, intraspecific morphological variation and sexual dimorphism are discussed and its biogeographical distribution mapped.