444 ME. w. B. coi/LiNGB ON KtmoPEAN SLUGS. [May 4, 



brown to pale j^ellow, when of the latter colour they are usually 

 more intense in the region of the caudal pore. Long. max. 

 40-55 millim. 



There is a single vestibule, from which the sperm-duct opens in 

 the form of an expanded tube ; it is comparatively larger than in 

 A. suhfitscus, and is folded upon itself at the point where the vas 

 deferens commences, which organ is also considei'ably longer than 

 in A. suhftiscus (Pis. XXX. & XXXI. figs. 13-14). The free- 

 oviduct is a long, wide, and somewhat S-shaped tube. In none of 

 the specimens 1 have examined does it approach the form so 

 characteristic of A. subfuscus (PL XXIX. tig. 1, f.ov.). The re- 

 tractor muscle is attached about the middle, whereas in subfuscus 

 it is attached to the upper third. The receptacular duct is long 

 and thin, expanding at its head into the spherical receptaculum 

 seminis. The retractor muscle is attached to the duct just below 

 the bead. The common duct is thrown into a series of convolutions 

 terminally, and shorter than in subfuscus. The hennaphrodite 

 gland is a small, dark-coloured, ovoid or pyriform body with a long 

 convoluted duct. 



Babor's description of the reproductive organs of A. citrinus, 

 "Wester. (2), leaves no doubt as to \x being Miiller's A. fuscus. I 

 have reproduced his careful figures of these organs (PI. XXXI. 

 figs. 15-16), and also those of the variety boeUgeri, Poll. (PI. XXXI. 

 fig. 17), which according to this author is characterized anatomically 

 by the short receptacular duct, a feature which I can confirm. 



5. Description of a new Species of Arion. 



In 1892 (5) I recorded a new variety of the well-known Arion 

 hortensis, Per., under the name of cceruleus. The specimens had been 

 very kindly sent to me from Ireland by Dr. E. P. Scbarff. I 

 pointed out in the description of this variety that possibly, when 

 further investigated, its anatomical characters might prove to be 

 more permanent than I then supposed. ISince that date specimens 

 have been sent to me by Mr. B. B. Woodward from EaUng (10), 

 by Mr. H. Horsman Macnabb from Heaton, Lancashire, and I have 

 myself collected examples near Oxford and elsewhere. After 

 having made a careful examination of this material, I feel convinced 

 that this form is sufiiciently distinct both externally and internally 

 to be separated from A. hortensis, Per., as a distinct species. 



Aeion czebuletts, sp. nov. 



Arion hortensis, Per., var. cceruleus, CoUinge, Conchologist 

 1892, vol. ii. p. 26. 



Body blue or greyish blue, with conspicuous dark blue lateral 

 bands, and pale yellow ground-colour between these and the foot- 

 fringe ; mantle with dark bluish central patch, and darker bands 

 at each side ; head and tentacles bluish grey ; foot-fringe white, 

 usually without lineoles ; foot-sole white or very pale yellow ; 

 rugae ilat, large, and elongated ; sulci dark . 



l/ength (in alcohol) 27-33 millim. ; alive 43 milhm. 



