138 Journal New York Entomological Society. [Voi. xxiv, 



approximate correspondence in position of the two primaries of the 

 first stage (which we agree to be iv and v) with the two lower of 

 the later stages, leads Fracker to believe them the same ; from the 

 same data however I concluded that iv and v, which are very high 

 even in the first stage, had moved considerably farther, and that vi 

 had appeared as usual below them. The problem could only be 

 settled by a full study of the muscular system, and determination if 

 the organs of that part of the body have moved up, or by definitely 

 locating the subventral fold, which runs in the Frenatte between v 

 and vi. The first is impossible in the complete lack of material, but 

 a specimen before me shows most of the dorso-ventral muscles in the 

 last stage (see figure). The two folds (the subventral and psi) 

 are both formed by intermediate insertions of the retractor muscles 

 of the proleg, etc. ; we find in Hcpialus the most dorsal of these in- 

 sertions, defining the subventral fold, are immediately below the 

 spiracle; and far above, not below, the seta which I interpret as vi. 

 A second insertion appears below vi, which I interpret as marking 

 the fold psi. I then rest in my former opinion that the three setae 

 are iv, v and vi, not a new subprimary, iv and v. 



Next in order is the homology of the meso- and meta-thorax with 

 the abdomen. I think we are agreed that i is alpha, ii is beta, x is 

 gamma (four set^e on the thorax,* both in Jugatae and Frenatse) ; 

 vii a and b are nu and pi, vii c is tau, viii is sigma and ix is omega. 

 The difiference then is in Dr. Fracker's assumption that the number- 

 ing used was intended to imply homotypy, which was the case only 

 with the ventrals and small primaries ; and in the lateral region, com- 

 prising iii, iii a, iv, v and vi on the abdomen, and epsilon, rho, kappa, 

 theta and eta (delta, rho, kappa, theta, and epsilon in the Jugatae) of 



4 It has been a puzzle to me for some time why the mesothorax has three 

 setje in group X, while the metathorax has four. Y. H. Tsou, in the Trans. 

 Anicr. Micr. Soc, XXXIII, 223, has recently given a satisfactory explanation, 

 namely that one of the normal four setje has moved across the incisure to the 

 prothorax, where it has been generally overlooked or treated as a secondary 

 prothoracic seta. In other points I am inclined to disagree with Mr. Tsou 

 for the same reasons as with Mr, Fracker. And why should two papers froir 

 the same laboratory on the same subject worked out at the same time use 

 entirely different nomenclatures for the same structures ! One paper must be 

 translated before it can be compared with the other, and then we find that in 

 other features they are often in agreement. 



