23 



lininiiiL,' tlic liiglicsl siil)l;imily nf the I'luiln it'uhv. I \\\\\ ;i\\;in; lliiil llii' 

 l;irv;v' liiivc sixteen leel. no dtlier I'liiil.-enul li:t\inif more than I'onrteen. 



Eiift'ti. — There ai'e no peculiarities in the eyes sntlieienlly niari\e(l lo 

 (lislingnish llw jrenei'a and species. They ai'e lull, spheiical, (lotted with 

 black spots, and jjrovided with scattered, short, minute hairs. 



OccH'i. — Altliougli it is stated* that tin; Pliahenldcc have no ocelli, 1 have 

 fonnd that tiioy generally occur in o;ir species; thongli, compared with those 

 ot" the Nodttida, they are small, and easily overlooked. Th(>y are situated 

 ver}' near the eyes, usually on the sufnic l)et\\een the epicraniuin and occiput. 

 They sometimes appear as il" actually sitinitc'd on the occiput, l)ut thi.s is not 

 the case, as theii" normal site is the posterior ed<re of the ci)icraniuni. 



They are [U'esent or alisent in diil'erent species of the same genus. For 

 e.\ainj)le, in Soniothiya quadri-signata they are unusually large and distinct ; 

 wiiile, in iS. ocelliiiata, they are entirely absent. It is a question whether they 

 are ever of use to the insect, as, in most cases, they aj)pear as if partially 

 aborted, and their presence and absence in different species of the same 

 genus shows that they are not very essential to the life of the insect. 



They occur in vai'ions degrees of [)erfection in the Ibllowing species: 

 (UnHCopteryx ctesiata, Plcnnjiia Jh/r/.al/i, Hydriomena tr'ifascinfa, Ochyria 

 designata, Melanippe iitficiUata and haytatu, Vlnhalapteryx intc.stinata, Eucos- 

 mia undulata, Bapta (dboolltala, Heterophelps trlguttata, Zcrene catenaria, 

 Semio/hisa quadri-signata, Azellna hiihncrarin, Tephrosin cnnadaria, Metrocnm- 

 ]Hi pey'laiia, Caripeta dlvisata.Acidalia qiwdn'-Zii/eafa, Kucrostis chlorolcucaria, 

 xMetaneina inatomaria, Endroi)ia hypochraria, Cahcrodes corifiisaria and niclro- 

 aimparia, Eutropdu Iransrersafa, Cydlmon Leiliis. 



The following species were found (o have no ocelli : Eupitliecia 7niseru- 

 litd, Pefrophora pninnta and /'. dircr.^/iinra/a, Oporinia pcrUnenta, SfviiotJtisa 

 oceUlnata, Aimopteryx pometar'm, Cymatophora crepuscularia, Nematocampa 

 Jitamentaria. 



§5. COMPAKATIVE AnATO.MY OF IV.V. TlIORAX. 



Ill studying the anatomy of the thorax of the Phakenida, as compared 

 with that of other families of the Lepidopt(!ra, we are l)atlled Ity th(! want of 

 a comparative knowledge of the parts ol" the thorax in this and other orders 

 of insects. It is the writer's intention to prepare a work on the comijurative 

 e.xternal anatomy of insects, and he has collected some materials for the piir- 



*A. Gr.L'uCe. rhak'iiitcs. 



