94 The Irish Naturalist. May, 



ON THK ANATOMY OFVITRINA PYRENAICA, 



BY RKV. K. W. BOWEI^L, M.A. 

 [Pl,ATK 4.] 



Last \-ear Mr. Keniiard kiiidl}- sent me for examination two 

 living specimens of the new Irish Vitrina which Mr. Grierson 

 had sent him. I at once pronounced them to be V. pyreiiaica^ 

 Fer., tliough I was aware that they had been ascribed by a 

 high authority to F. eloiigata (se7Jiilimax) ; and that Simroth's 

 figure of the genitalia of that species had been copied in illus- 

 tration of them.^ I have taken both these species myself in 

 p'rauce. • Recently Mr. Kennard sent me eight more speci- 

 mens of the Vitrina. which had been collected by Mr. R. A. 

 Phillips in Co. Louth, March, 1908. I was especially glad to 

 have this extra material, as it has enabled me to verif}' and 

 correct my former dissections. All doubtful points have been 

 elucidated by paraffin sections of properlj'-fixed specimens. 



In Plate 4, figures A, B, and C represent the shell. The 

 actual length of the example drawn is 4 mm. Figures E, F, 

 G, and H are on the same scale. They were traced with the 

 Abbe camera from the actual objects. The most remarkable 

 feature of the shell is its extreme obliquitj' ; in order to see the 

 spire and the lower margin of the peristome at the same time it 

 must be held at an angle (as at C), when its flatness is also 

 apparent. In the living animal the shell rests on one side of 

 the visceral hump, inclined at an unusual angle to the vertical 

 axis, as will be seen by comparing figures A and D. This 

 last figure shows the animal in about an average state of ex- 

 tension ; it is capable of still further elongation, and is also 

 able, when at rest, to assume very much the .same shape as 

 Agriolimax IcBvis. When the animal is extended, the walls of 

 the atrium (which are very thin and flimsy) are drawn out, 

 as shown in figure K ( V. pcllucida). But the flagelhim, 

 vagina, and proximal parts of the epididymis are also capable 

 of considerable extension ; thus the end of the flagellum is 

 often found retorted, as in fig. E- The external genital orifice 



^ J. \V. Tavi.ok, '• Vitrina eloiigal.a in Ireland," Uish Nat., vol. xvi., 1907, 

 pp. 225-231, pi. 26. 



