1907- Taylor. — Vitri?ia elongata in Ireland. 229 



carinate, obliquely grooved, and delicately speckled with 

 slate grey. Foot linear and whitish. 



The shell is flattish, very thin and fragile, smooth, extremely 

 glossy and transparent, with a very pale yellowish or greenish 

 tint ; the spire has \\-2 whorls, the last forming nearly all the 

 shell ; suture shallow and not distinct ; apex flat and not pro- 

 minent, umbilicus none. Aperture exceeding two-thirds the 

 greatest diameter of the shell, of a rounded oval shape, hardly 

 interrupted by the penultimate whorl -; columellar and basal 

 margin very arcuate, with a very broad and striking mem- 

 branous fringe. Length of shell 4-5 mill., breadth 2*5 — 3*5 

 mill., height 1*5 — 2 mill. (Plate 26, fig. 1.) 



Internally we find important and striking differences ; the 

 ovotestes are connected by a simple, direct and scarcely convo- 

 lute hermaphrodite duct with the pale and inconspicuous 

 vesicula seminalis at the base of the lobulate albumen gland ; 

 the short-stemmed oval spermatheca arises from the free ovi- 

 duct near the origin of the vas deferens ; the penis is simple, 

 short, thick, and very glandular the vas deferens entering 

 near the end, opposite this organ' and opening also into the 

 atrium is a well-developed dart sac and glandular appendage, 

 composed of a lower or basal part with thiunish walls, at the 

 end of which is a strong and perforate projecting papilla 

 which forms the outlet of a gland and leads through a chitinous 

 and curved love dart, which is of a pale brownish colour and 

 widens at its free end into a funnel-like termination with 

 jagged margins. (Plate 26, figs. 3-5.) 



Compared w 7 ith the better-known V. pclhicida, we have in 

 elongata a larger animal relatively to the shell, which is quite 

 incapable of containing the body, and which is itself almost 

 concealed by the overspreading mantle margin. 



The shell, which in V. pclhicida is globular and contains 

 three to four whorls or coils, has in elongata scarcely half that 

 number, and is very flat with an insignificant spire, and also 

 possesses a very broad membranous fringe destitute of cal- 

 careous stiffening along the lower margin; this feature, which 

 is scarcely perceptible in pclhicida, being an indication of the 

 progress of the degeneration of the shell. Internall3 T , a differ- 

 ence is shown by the spermatheca, which is an oval vessel with 



