BY N, A. COBB. 175 



Cuticula. 



Concerning the cuticula I have little to say beyond stating that 

 it is composed of three layers and exhibits under the highest 

 magnification fine transverse strife. There is no indication of the 

 future cuticular growth at the head unless two large cells, one 

 placed dorsally and the other ventrally, be so considered, and I am 

 doubtful if that can be done. These cells are pointed out at d, d. 

 Fig. 2. On the other hand the wings are to be distinctly seen 

 and apparently extend from one end of the larva to the other. 



Tlte Alimentary Cayial. 



The mouth is as yet unprovided with distinct lips. The saucer- 

 shaped mouth-cavity leads to an oesophagus which is most appropri- 

 ately likened to that prevailing in the genus R h a b d i t i s, that is to 

 say the anterior half, which is swollen at its posterior extremity, is 

 connected by a narrow passage with an elongated-ellipsoidal jiosterior 

 bulb. This bulb sometimes does and sometimes does not show 

 traces of the future valvular apparatus. The swelling at the 

 posterior extremity of the anterior half of the cesophagns seems to 

 me to have the signification of a bulb, but while the posterior bulb 

 is composed of numerous small cells, this median bulb, as I will 

 term it, is composed of about six large elongated cells whose long 

 axes lie in the direction of the oesophagus. In the remaining 

 parts of the oesophagus the cells present large elongated nuclei. 

 The intestine, at first narrow, gradually widens to the middle of 

 the body, where it has a diameter one-third as great as that 

 of the body itself, and then continues with a uniform width 

 until near the anus, where it presents a broad constriction 

 similar to that figured by Galeb* for the larvge of some 

 species of O x y u r i s parasitic in insects. I do not think that 

 this constriction corresponds to the beginning of the rectum. I 

 am not certain what its signification is. I have observed an 



* "Organisation et developpemente des Oxyurides. " Arch. d. Zool, Exp. 

 VII. 1878. 



