WATSON : DEFICIENCIES IN THE VERTIGININ^. 273 



Vertigo alpestris, Alder. 



Ten specimens collected by Mr. Charles Oldiiam at Dolgelly, 

 Merionethshire, in September, 1921. — In eight of these specimens no 

 penis can be seen, but as some of this material is not in good condition 

 it is only possible to say with certainty that the penis is entirely 

 absent in the case of four individuals. The first part of the vas 

 deferens is present beside the oviduct, but it ends blindly, sometimes 

 in a slight swelling, at about the level of the anterior end of the 

 receptacular duct or a little below it. 



The hermaphrodite duct is darkly pigmented, and is somewhat 

 swollen near its anterior end to serve as a vesicula seminalis. The 

 hermaphrodite gland, the small prostate, and the spermoviduct are 

 similar to those of the preceding forms. The glandular oviduct is 

 rather large, the non-glandular free oviduct is very short, and the 

 vagina is rather long. The receptaculum seminis lies beside the 

 posterior end of the spermoviduct near the albumen gland, and has 

 a very long duct. 



In the remaining two specimens of this batch male organs are 

 present. The penis is very long, and is lined by glandular cells 

 containing a granular secretion. The vas deferens enters the penis at 

 its extremity ; it is very long and slender, and the last part of it 

 does not appear to be broader than the rest. The genital atrium is 

 very short. The remaining genital organs of these two specimens are 

 similar to those found in the examples without a penis. 



One specimen collected in the same locality in October, 1922, is 

 without a penis, and closely resembles the similar specimens collected 

 on the previous occasion, except that the vas deferens is somewhat 

 longer, reaching to the neighbourhood of the genital opening, where 

 it ends blindly in a slight swelling. 



The evidence of the genital ducts does not support Boycott's 

 suggestion that this species might prove to be viviparous.^ On the 

 contrary, it seems very unlikely that any of the species dealt with 

 in this paper are viviparous forms, judging from their structure. 



Vertigo pusilla, Mtill. 



Ten specimens collected by Mr. Charles Oldham at Dolgelly, 

 Merionethshire, in June, 1922, and seven more found in the same 

 locality in October, 1922. — The whole of these seventeen specimens 

 are destitute of a penis ; but they possess a Vas deferens, which is 

 usually of some length, though it does not lead anywhere. The 

 hermaphrodite gland and its duct, the prostate gland, the 

 spermoviduct, the glandular oviduct, and the free oviduct and 

 vagina are all of the same type as in the last species ; but it is 

 noticeable that the secretion in the posterior end of the spermoviduct 

 stains more deeply with haematoxylin than that in the anterior part 



1 Proc. Malac. Soc, vol. xiv, 1921, p. 172. 



