336 NEOTROPICAL PSELAPHIDAE 



segments not longitudinally impressed as in germaini but very slightly flattened. 

 Penis partially exserted to assure sex of type. 



Metasternum 0.335 mm. long, medianly broadly concave. Immediately an- 

 tero-mesiad of each posterior coxa is an elongate subcarinoid tubercle, and in 

 the exact center of the metasternal length, on each sloping wall of the concavity, 

 is a minute hook-shaped process or an anteriorly directed microtubercle ; apical 

 margin medianly incised as usual to accommodate intercoxal tubercle of first 

 sternite. 



Legs simple save that the posterior tibiae are spurred. This spur arises quite 

 basad of apex; for quite a distance the coarse setae emerge to give a straight, 

 thick, very obliquely truncate bundle. 



Described on a single male from Corumba, Matto Grosso, Brazil. 



This new species has the antennae of germaini and the metasternal micro- 

 tubercles of tuberculatus in addition to a pair of juxtacoxal tubercles. It is pos- 

 sible that the variation in antennomeres and male characters is great within the 

 genus, in which case tuberculatus and sternalis may be varities of germaini, and 

 simplex the female of one of these male variations. Such a condition is not prob- 

 able. Study of antennomeres in Reichenbachia, Arthmius, and both subgenera 

 of Hamotus suggest a genetic ratio between length and width of a segment in 

 the same sex of a given species of pselaphid. That is, the third antennomere for 

 example, if obconical will vary in length but is never wider than long; or if this 

 segment is more or less transverse, it will vary in width but is never longer than 

 wide. Such study requires long series of specimens. Since Cercoceroides is not 

 common in collections, this approach must be delayed. 



The species may be tabulated as follows: 



germaini (Raffray). 1890. Matto Grosso, Brazil. Genotype. (Cerco- 



cerus) 

 laticeps Raffray. 1917. Asuncion, Paraguay.* 

 pectoralis Raffray. 1911. Merida, Los Andes, Venezuela. 

 simplex Raffray. 1904. Matto Grosso, Brazil. 

 sternalis new species. Corumba, Matto Grosso, Brazil, 

 tuberculatus Raffray. 1904. Matto Grosso, Brazil. 



PSEUDOHAMOTUS (Raffrey, 1890) 



This neotropical genus holds five species having many notable affinities with 

 Hamotoides but distinctive in the form of the last segment of the maxillary 

 palpi (PI. XX). 



This distal palpomere is more or less semicircular in outline, nearly as broad 

 as long, with external face consequently very convex; the internal face is sub- 

 rectilinear and bears an entire but very narrow sulcus ; as usual in the hamotine 

 stem, the palpal cone is obliquely inserted at the apex of this sulcus. 



' I have recently received a female of this species from Horqueta, Paraguay, collected 

 December, 1935, by A. Schulze. This checks with Raffray's description and has not since 

 been reported. 



