274 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



of the same duct, the contrast being somewhat strikiiig, although 

 the structure of the two parts is similar. The receptaculum seminis 

 appears to occupy a similar position in this species to that which it 

 does in the preceding forms. 



It wiU be noticed that the above description does not agree with 

 Lehmanns figure bi, which shows a penis; but there is some doubt 

 as to whether this figure really represents the reproductive organs 

 of Vertigo pusilla, which are not described in the text ^ ; it seems 

 possible that it may portray the genital organs of F. angu-stior, 

 which Lehmann does describe. 



Truncatellina britannica, Pilsbry.^ 



Fifteen specimens collected by Dr. Boycott at Branscombe. South 

 Devon, in August and September, 1922. — Twelve of these snails are 

 without male organs, except that in. at least some individuals there 

 may be a vestige of the part of the vas deferens near the .oviduct. 

 The hermaphrodite gland, unlike that of the preceding species, is 

 divided into two separate portions. The outer side of both parts is 

 coated with a thick layer of pigment. The hermaphrodite duct is 

 also darkly pigmented, and is only very shghtly swoUen towards its 

 anterior end. Xo prostate gland could be found. The broad glandular 

 duct passing forwards from the albumen gland consists of three 

 successive portions, instead of only two, as in the preceding species. 

 These three portions differ widely in their histological structure. 

 The first or posterior portion has a thick compact epitheHum of 

 oblong secretory ceUs, like those commonly found in the waU of the 

 sperm oviduct. In the second or middle portion we find large rounded 

 glandular cells, with clear contents. In the third or anterior portion 

 there are smaller ciliated gland-ceUs, the secretion of which stains a 

 bluish colour with hasmatoxylin. The receptaculum seminis lies 

 against the outer side of the jimction of the second and third of 

 these portions ; its duct is therefore much shorter than in the species 

 already described. The non-glandular free oviduct is short, and it 

 and the vagina in front of it are of the same simple type found in the 

 preceding forms. 



The three other specimens found with the twelve just described 

 are similar, except that they possess male organs. The vas deferens 

 is of moderate length, and leads into the posterior end of a rather 

 smaU penis without any apparent glandular tissue. Xo penial 

 appendix was found, such as is described and figured by Lehmann 

 in two other members of this genus. ^ It is possible, however, that 



1 Op. cit., pp. 153, 319. 



^ This form may be a subspecies of Truncatdlina rivierana (Benson) = 

 T. strobeli (GredJer), as Pilsbry supposed {JIan. Conch., ser. n, vol. xxri, 1921, 

 p. 77). The name was originally spelt " brittanku ", but I am informed that 

 this ■was a printer's error. 



3 Op. cit., pp. 140, 14S, pi. xiii, fig. 47 ; pi. xiv, fig. 51. 



