Generative System in the Genus Testacella. 23 



the direct continuation of that organ. The receptacular duct 

 arises from the most anterior portion of the vagina ; it is a 

 fairly wide tube, which opens into a dilated and slightly 

 oval-shaped sac, the receptaculum seminis. The vagina in 

 the majority of the Testacellidee is of great length. This 

 feature is more marked in T. scutulum and T. Maugei than in 

 this species. It is continued as the oviduct and prostate — 

 the common duct of many authors. There is a large albumen- 

 gland present, which calls for no special mention. The 

 hermaphrodite duct is a densely convoluted canal leading 

 from the hermaphrodite gland, which is usually of an oval 

 form. 



Testacella scutulum^ Sowerby. (PI. I. fig. 2.) 



This species has been classed as a variety of T. haliotidea 

 by most of the writers upon the British MoUusca. 



It was described and figured by Sowerby in 1823, in his 

 ' Genera of Recent and Fossil Shells.' Fcrussac, who in 

 the same year examined specimens, came to the conclusion 

 that it was but T. haliotidea^ with which view Mr. Sowerby 

 agreed, and since then it has been regarded as a variety of 

 that species by Gray, Forbes and Hanley, JeiFreys, Rimraer, 

 and other authors. It was redescribed as a new species by 

 Mr. Tapping in 1856, as Testacella Medii-Templi. In 1886 

 Mr. Charles Ashford made anatomical examinations of the 

 slug and clearly proved its specific distinctness. An account 

 of his work is embodied in a paper previously referred to 

 (Journ. Conch. 1888). Although to Mr. Ashford is due the 

 credit of having placed this slug in its proper position, the 

 above-mentioned account, botli description and figures, leaves 

 much to be desired. 



The distinctness between vestibule and vagina is scarcely 

 perceptible in this species. The upper part of the vagina is 

 dilated in a pouch-like manner, but narrows previous to 

 entering the oviduct. The penis is a large muscular organ 

 and readily distinguishable from that in the preceding species, 

 being rather shorter and always much broader. It opens 

 into the vas deferens. There is no fiagellum. The penal 

 retractor muscle is attached laterally to the penis. The 

 receptacular duct leaves the vagina as a broad pouch-like 

 organ, and continues as such for quite two thirds of its length, 

 when it tapers off suddenly into a narrow and short tube, 

 which opens into the small globular receptaculum seminis. 

 Judging from the peculiar form of the receptacular duct and 

 the internal structure, I think it is very probable that the ova 



