92 NEOTROPICAL PSELAPHIDAE 



narrower pyramidal apical portion, about one-fourth as long as basal piece. 



Maxillary palpi four-segmented, first segment short, thick, one-third as 

 long as second, and articulating obliquely with second; second segment short, 

 subconical with the basal width narrower than first segment; third segment 

 slightly wider than the inflated apical end of the second, and half as long as 

 second, subspherical ; fourth three and a half times longer than third and twice 

 as wide, ovate, with a truncate apex bearing a very long, blunt palpal cone. 



Pronotum with simple apical and basal margins, the surface asperate- 

 tuberculate, especially the lateral margins which are strongly crenulate ; broad- 

 est at middle ; a short median carina extends from the basal margin to a large 

 subbasal, transversely fusiform fossa; three minute foveae on each side of the 

 basal carina, at basal margin; a deep lateral fovea on each side of this median 

 depression, the three connected by a transverse subbasal sulcus; anterior half 

 of disc with a median, longitudinal, fusiform foveoid depression. 



Scutellum elongate-triangular, small. 



Elytra lightly punctate; each elytron with prominent, oblique, subdentate 

 humeral angle, three basal foveae arranged in the typical form for the genus, as 

 noted previously; subhumeral fovea recessed beneath the humerus, and asso- 

 ciated with a long subepipleural sulcus on the flank. 



Abdomen with six tergites visible, first very short and exposed at base of 

 elytra, one-fourth as long as second (normal first visible tergite for pselaphids) ; 

 second one-third longer than third; third and fourth and fifth subequal in 

 length; sixth very short, as long as first, and transversely triangular. Second 

 tergite with a transverse depression in basal half, and half the segmental width. 

 Seven sternites, of which the first is triangular between the coxae; second 

 longest, with a short, deep and wide depression in basal third; third sternite 

 one-third shorter than second; fourth slightly shorter than third; fifth medianly 

 short, one-half as long as fourth, the apical margin broadly concave; sixth with 

 basal margin broadly convex, fitting the fifth, but with apical margin medianly 

 deeply incised to contain the small, circular seventh; seventh sternite articulat- 

 ing with the abdomen on its right side, and swinging to the right to permit 

 extrusion of the penis, measurements of which have been given. 



Prosternum with anterior margin strongly dentate, and with a strong 

 median, longitudinal carina from coxal cavity to apical margin, entire; lateral 

 prosternal foveae well formed. 



Mesosternum with a median, longitudinal carina; prepectoid alutaceous. 



Metastemum very long and broad. Sternal foveae of the raeso- and meta- 

 sternal fields well developed and all paired to give a high (primitive) number, 

 foveae II, III, IV and VI typical, and in addition a pair of foveae rarely found 

 (Posterior Mesosternal Foveae) which penetrate between the posterior-lateral 

 angle of the mesosternum and the mesocoxal cavity on each side. Thus barro- 

 coloradoensis has two prosternal, and ten meso-metasternal foveae. 



Middle coxae distinctly separated by the union of a truncate process from 

 the mesosternum and metastemum. Posterior coxae very short, triangularly con- 

 ical, almost contiguous. Femora only moderately inflated. Tarsi relatively short 



