130 



E. A. ANDREWS. 



This second fold is slightly developed in this case. In another 

 specimen, Fig. 15, the groove bent very far to one side and the 

 anterior part was concealed under the second fold. We will call 

 this second fold the "transverse" fold, since it ultimately lies 



FIG. 14. 



FIG. 15. 



more nearly across the median plane. Both folds are oblique, 

 the "hood" and the "transverse" fold being about at right 

 angles where the latter passes under the former. In Fig. 1 5 

 not only is much of the groove overhung by the transverse fold, 

 but the entrance to the groove in under that fold is cut off, near 

 the hood, by a short posterior fold that runs parallel to the 

 transverse fold as it emerges from under the hood. 



The cases of unusual bending of the groove to one side sug- 

 gest the state of things found in the adults of *C. immunis and 

 C. Bartoni where the receptacle is more transversely placed than 

 in C. affinis. 



The specimen last figured was about to shed and the delicate 

 new shell within the one here figured was more like that figured 

 below for the next stage. 



In another case the shell cast off by a larva going into the 

 sixth stage had the groove but slightly bent, Fig. 16, and the 



FIG. 16. 



FIG. 17. 



transverse fold was less oblique. As there was no fold opposing 

 the transverse fold an object could have passed under its pos- 



