LEE BARKER WALTON 9 



gemiina) in Hydrous piceus, as the metathoracic trochan- 

 tin. Among the recent writers on insect anatomy, 

 Packard^ confuses the trochantin with the meron; Miall 

 and Denny^ hold that the occurrence of the joint apphed 

 to the coxa (trochantin) "is so partial" that it need 

 scarcely be taken into consideration; Sharp- believes with 

 Packard that the posterior part of the coxa (meron) in 

 Panorpa represents the trochantin; while Comstock,"* in 

 a description of the metathorax in Ejichromia gigantea, 

 agrees essentially with the preceding, although he cor- 

 rectly figures the trochantin of the prothorax and meso- 

 thorax. Lownc'^ regards the piece termed by him 

 "epitrochlea"*^ as "certainly the trochantin of Audouin," 

 ignoring his previous suggestion that one should adhere to 

 the rule of priority. Several other writers, notably Latzel 

 (Chilopoda), Comstock and Kellogg (Lepidoptera), and 

 Kolbe (Lepidoptera, Trichoptera, and Panorpa), have 

 mentioned the existence of an apparent suture in the coxa 

 of certain groups under consideration, but without 

 attempting to discuss its meaning. 



Immediately in front of the metathoracic coxa, par- 

 ticularly among the Coleoptera, a small sclerite is discern- 

 ible, which bears the name of antecoxal piece. This is 

 also well shown in Cicada, some species of which {Cicada 

 dor sat a) possess a piece homologous with that found in 

 the Coleoptera; while in others {Cicada tibicen)'^ instead 

 of being chitinized, the part is often membranaceous in 

 structure, and serves to retain the coxa more firmly in the 

 coxal cavities, thus indicating its origin; and the presence 

 of a homologous piece in the mesothorax of many Coleop- 



Systematic Position of the Orthoptera in R'^lation to the Orders of Insects. 

 Third Report U. S. Ent. Cam., 1880-82. A Text-Book of Entomology, p. 95, 1898. 



The Structure and Life History of the Cockroach, p. 61, 1886. 

 ^Cdmb. Nat. Hist., vol. v, p. 104, 1895. 



^Manual for the Study of Insects, p. 504, 1895. It was due to Professor Com- 

 stock's suggestion of a possible error in considering the lateral margin of the meta- 

 thoracic coxa of Euchromia as the actual homologue of the mesothoracic trochantin, 

 that the study leading to this paper was commenced. 



The Anatomy, Physiology, Morphology, and Development of the Blow-Fly, 

 vol. i, p. 179, 1890-92. 



The homology of this with the trochantin appears doubtful. 



Although a good series was examined in which the other sclerites were well 

 chitinized, the absence of chitinization in the antecoxal piece may be the result 

 of immaturity. This, however, would not alter the conclusion. 



