42 Genitalia and Lingual 



A is taken from the least developed, or posterior end of the membrane. 

 Figs. B and C are drawn from intermediate points, the former from near 

 the centre. 



Marginal teeth from various points of the membrane are figured in E 

 and G, each tooth being numbered from the median line. Fig. F shows 

 an extreme marginal in profile. 



Near the outer edges of the membrane the teeth are not only much 

 smaller, and arranged more obliquely, but they are more separated from 

 each other on the same transverse row, and the rows themselves are not 

 so crowded together as in the portions of the membrane nearer the 

 centre. 



On dissecting the animal I found nothing of peculiar interest in the 

 digestive, respiratory or nervous systems. There appeared to be the 

 same general arrangement as figured by Dr. Leidy (Terr. Moll. U. S., I, 

 pi. v) for the allied species, L. fasciatus. The same may be said of the 

 generative organs, which, however, I have figured (pi. IV, fig. G) to com- 

 pare with the figure I have given of the same organs in Orthalicus gallina- 

 sultana. The external orifice of generation is close behind the right 

 eyepeduncle. The testicle, epididymis and ovary were separated from 

 the specimen examined. The oviduct (8) is long, narrow, greatly convo- 

 luted. The genital bladder (9) is small and globose; its duct (1G) is long 

 and narrow; in its natural position it lies close against the oviduct: as 

 the duct joins the vagina it becomes enlarged to the size of the latter 

 which it enters at its upper third. The vagina is very wide below this 

 junction. The vas deferens (7) runs as usual along the side of the vagina 

 to its base, and thence to the summit of the penis where it enters. The 

 penis sac (5) is long, slender, "cylindrical, narrowing at its apex, into 

 which is inserted a long delicate retractor muscle (6) which might be con- 

 sidered a flagellum : the penis does not seem to enter the vagina, but to 

 have an independent opening of its own. Near its base it bears upon a 

 short pedicle, a single prostate gland, a multifid vesicle of the same type 

 as figured by Dr. Leidy in L. fasciatus, composed of about six short, ovate, 

 detached lobes. 



Thus it will be seen that Liguus virgineus agrees in its 

 genitalia with the allied species, L. fasciatus , but differs in 

 its shell, and in its lingual dentition. No generic value can 

 be placed upon this last character, however, for while L. 

 fasciatus resembles in its dentition Orthalicus undalus, me- 

 lanochilus, and. iostomus, its allied species L. virgineus is 

 characterized by a widely different dentition, which is shared 

 on the other hand in a great measure by Orthalicus gallina- 

 sullana. From our present knowledge we are forced to be- 

 lieve that lingual dentition will furnish no guide to the 

 generic distinction between Orthalicus and Liguus. 





