EN A. 229 



in size and becoming filiform, undulating, and terminating in a 

 curved, thin, long and club-shaped flagellum. The albumen gland 

 is elongate, lingulate ; the uterus broad, strongly wrinkled, the 

 vagina in length almost equalling the uterus. The vagina 

 branches above the penis, but on the other side, into the 

 sperraatheca duct, which is moderately, long and strong, equalling 

 the vagina in length and terminating in the spermatheca. 

 (Lehmann.) 



Jacobi, in his paper entitled " Japanische Besclialte Pulmo- 

 naten"*, when dealing with the Japanese Biiliniinus reiniamis, 

 Kobelt — referred to the subgenias Mines by Mollendorfi: — alludes 

 to the fact that Lehmann had already drawn attention to the 

 presence in Baliniinus [^Ena'] ohscurus of a peculiar organ — the 

 appendix — proceeding from the penis close to the atrium. In 

 reiniamis this organ is also present but possesses some special 

 characters. AVhile having the same diameter and possessing 

 equally solid walls as in obscwus, it is here only one-third its 

 length, while at its apex, after suddenly becoming attenuated it 

 is produced into an enormous flagellum equalling in length the 

 whole genital apparatus and slightly swollen at the extremity. 

 The appendix proper, near its contracted portion, is covered 

 internally with a mucous membrane, invested with an epithelium. 

 A little below this a powerful retractor muscle is attached. From 

 various considerations Jacobi comes to the astounding conclusion 

 that this organ is homologovi.s to a second penis. AVhile admitting 

 that cases of duplication of the sexual organs are unknown in 

 Mollusca, he refers to the presence of a double penis in many 

 snakes ! A far more rational interpretation of this organ is 

 provided by Dr. Simroth, in a footnote on page 82 of Jacobi's 

 paper, where he suggests that it is a dart sac with dart glands and 

 retractor muscle, but without dart, as it is known to occur in 

 Urocijclus and Parmarlon. 



The Indian species of Ena have a somewhat remarkable distri- 

 bution and those referred to the subgenera Suhzebrinus and Serina 

 at least must, I think, be regarded as immigrants from the 

 Pala3arctic region; the former, numbering eighteen species, show 

 a close affinity with Afghan, Turkestan, and Tibetan forms, while 

 the latter, comprising only five species, are probably more nearly 

 related to Chinese members of the group. Both subgenera are 

 confined to the uortli-western portion of India. The subgenus 

 31in(s, on the other hand, has three species in Ceylon, and two 

 occurring both in South(!rn India and Assam, one of the latter 

 having also been recorded from the Shan States, while only two 

 have been described from Xorth-AV'estern India. To judge from 

 its distribution this subgenus must therefore be regarded as 

 endemic. 



* Joiirn. Coll. Sci., Tokyo, xii, 1898, p. 76. 



