NKW N[AI.LOI'HA<iA. 163 



also ill Gyropiis, an Aiiiblyceraii inaininal-infesting 

 genus* 



111 some species of several genera the sclerite is not 

 of the typical form described. In Ducojihonis jjertusas 

 it is very much modilied in form. The body is com- 

 paratively very small and the anterior processes are not 

 present at all. On the other liaiid, tlu' lateral circum- 

 oesoplrageal Ijands are greatly enlarged, forming a thick 

 chitinous band passing uj)\vard around the pharynx. 

 The body of the structure is so small that it appears 

 merely as a median, backward-projecting enlargement of 

 the rest. The dorsal cavity is [)reseiit, its anterior wall 

 and the anterior margins of the lateral wings are trans- 

 parent and continuous with one another. The wings 

 are expanded near their bases but distally each becomes 

 narrowed and passes u})ward and somewhat forward as 

 a slender curved rod. The structure is of about the 

 same shape in a young specimen but the wings are pro- 

 portionally smaller. In DocophoviL>i atricolor the sclerite 

 is small and weakly chitinized but the anterior pro- 

 cesses are comparatively large and much expanded. 

 In Lipeut'us diversus the body is elongated, and in A. 

 sqiuilidiis it is similar but with the anterior i)rocesses 

 enlarged. In several other Ischnoceran genera the 

 sclerite is variously moditied, but the species in which 

 modification occurs are scattered and not closely related 

 to one another. 



lu the Amblycera only two genera possess the pharyn- 

 geal sclerite, and in these two the characteristic form is 

 not tliat (^f the Ischiiocera. It is, however, typically the 



"Tascheuberg tiguies Uothriometojnis viae roc nemis, S auil head of $, 

 aud Ornil/iobiits he.vojihthulmus, $ and head of 3 , iu which the sclerite is 

 uot shown. But iu Akidoproctus rostrutiin and .-1. iitti>op;/<jos it is plaiulv 

 preseut. Piaget liguies lioopia lomjitarsus, B. ijriindis, Kurcum rimi- 

 coides, E. mallcHx, dyropus ovalls, d'. ffracilis, aud '.'. turbinalis, iu all of 

 ■which the sclerite i^^ not shown. 



