NEOTROPICAL MALLOPHACxA — CARRIKER 413 



Rallicola. The circular posterior margin of the genital plate of the 

 female is sparsely set with short, fine setae. 



The male genitalia are of an exceedingly peculiar type, which seems 

 to be unique. The basal plate is short and rather wide; the parameres 

 very small and globular in shape (see figures); and the mesosome is 

 more strongly developed, with a large penis and rather heavy sup- 

 porting structures. 



Remarks: The genus Formicaphagus, as now known, is an extremely 

 liomogenous one, most extraordinarily so, considering the fact that the 

 species comprising it are parasitic on very distinct genera of hosts, but 

 all belonging to a single family. It is possible that some of the forms 

 here described are only subspecifically distinct from some of the others, 

 but no attempt has been made to make such distinctions. A very 

 careful analj'sis of their structures shows an amazing number of small 

 differences between them. The genitaha of all of the known males 

 are decidedly different, a ver}^ significant feature. Considering these 

 facts it has seemed best to classify them all as distinct species until 

 more material has been assembled from the many species of the host 

 family. 



Formicaphagus pictiiratus, new species 



Figures l,a,h; 4,e 



Types: Male and female adults from Myrmeciza i. immaculata 

 (La Fresnaye) collected by the author at Bellavista, Santander N., 

 Colombia, July 4, 1943 (USNM). 



Diagnosis: The head as long as wide in male (0.445), wider than 

 long in female (0.467 X 0.48). The premarginal carinae are wide, 

 with large nodi; anterior plate rather small, widest at tips of pre- 

 marginal carinae then converging posteriorly with straight sides; 

 preantennary margin of head concave. 



Sides of prothorax and pterothorax nearly straight, the latter with 

 sides strongly divergent and posterior margin with straight sides 

 running to an acute median point. 



The abdominal pleurites are wider in the female, both dorsall}^ and 

 ventrally, and are less pitchy black dorsally; the "heads" are much 

 longer in the female, especially the ventral portion. Whole abdomen 

 very clear (excepting pleurites), with tergites almost invisible; the 

 only visible sternites are the genital plate and sternite V, the genital 

 plate covering the median portion of sternites VI to VIII. 



In the male genitalia the basal plate tapers from near basal portion 

 to the narrowly rounded tip; the parameres are of medium size, en- 

 circled by a stronglj^ chitinized carina, and the component parts of 

 the mesosome are slender and more delicate than in most species of 

 the genus. 



