20 U.S. NATIONAL MUSEUM BULLETIN 248 posthumous 



Menacanthus hoffmanni, new species 

 Figure i:ll,a,b 



Holotype, cf adult and 1 d' paratype from Melanerpes aurifrons hoffmanni 

 (Gabanis), collected by the author at Juan Vifias, Costa Rica, March 

 1902. Type in USNM. 



Diagnosis: The frons is decidedly circular, more so than in praecursor, 

 and the temples are narrower, but since hoffmanni is a male, comparison 

 as to size is impossible. The thoracic segments are of the same shape, but 

 the coxae and femora are of very different shape (see figure). 



The male genitalia are unusually small, especially the basal plate, and 

 the movable sclerite is different from all of the others that have been seen 

 in this group. 



See key to species for further details. Measurements of types are given 

 below. 



Holotype, c?" adult, and only specimen, from Melanerpes formicivorus 

 flavigula (Malherbe), collected by the author at Virolin, Santander, Colom- 

 bia, Sept. 16, 1943. Type in USNM. 



Diagnosis: As stated above, this species may be compared only with 

 M. hoffmanni, since the three other closely related species are represented 

 (in the author's collection) by females only. It is larger than hoffmanni 

 in all measurements except the length of head, which is the same. The 

 head is wider both at frons and temples, with sides of frons flattened (per- 

 fectly circular in hoffmanni) ; the head spines are curved instead of straight, 

 the temples are wider, and occiptal margin less concave ; sides of prothorax 

 are convex, straight in hoffmanni; the coxae and femora are differently 



