NEOTROPICAL MALLOPHAGA — CARRIKER 411 



of tho 12 species represented by males have similar genitalia. 



In all the years of my collecting I have taken no Ischnocera from 

 any Formicariidae other than those included in these two new genera, 

 with but a single exception. The exception is a series of 11 speci- 

 mens of both sexes of a species of Sturnidoecus that were taken on 

 Batara cinerea excubitor collected at Samaipata, Bolivia. There is 

 no question as to the host, since I distinctly recollect having removed 

 the lice from the bird before it was skinned. The circumstances were 

 unusual, since it was my first taking of the genus Batara. 



It therefore seems logical to suppose that these two genera of 

 Mallophaga are the common parasites of the Formicariidae, the one 

 found only on the genus Formicarius and the other on all the remaining 

 genera, as far as now known. 



The presence of this very distinct genus of Mallophaga on Formi- 

 carius and the absence of the other genus foimd on the rest of the 

 family present a problem which the ornithological systematist may 

 very well ponder with care, since there is a remote possibility that 

 Formicarius may not be a Formicariidae at all. These birds certainly 

 have a very different appearance in life from all other Formicariidae, 

 although theu- whistling call-note does resemble a few species of the 

 genus Grallaria. 



I believe that a very careful study of the anatomy and osteology 

 of this genus of birds should be made, as well as of its nidification. 

 To my knowledge, I have never seen the nest or eggs of any Formi- 

 carius. 



With one exception, all of the species of Mallophaga described in 

 this paper were taken by the author from birds collected by him or 

 his assistants, so that it has been possible to detect most of the obvious 

 cases of "straggling" that inevitably present themselves. In many 

 cases of this so-called "straggling" the true host was easily detected 

 by making a check of the species of birds collected on the same date, 

 but when such measures failed to give a satisfactory solution the lice 

 were discarded in most cases. 



All measurements given are in millimeters and decimals thereof, 

 and were made with a properly calibrated eye-piece micrometer. All 

 figures presented are from drawings made by the author, who is 

 responsible for any errors which may later be discovered. The draw- 

 ings were all made by means of exact measurements taken with the 

 eye-piece micrometer; no "camera lucida" was used. 



Formicaphagus, new genus 



Genotype: F. picturafus, new species. Host, Myrmeciza i. im- 

 macvlata. Small species of Ischnocera parasitic on many genera of 

 the avian family Formicariidae (except the genus Formicarius). 



