ARION CIRCUMSCRIPTtlS. 



229 



The ALIMENTARY SYSTEM has tlie usual triodromous intestinal coiliu"' but the 

 tracts are shorter, and therefore do not so palpably shew the great spiral torsion 

 to which the viscera liave been subjected ; the OJSOPHAOUS is about three mill in 

 length, and fnsed to the pharynx ; the CROP is dirty-brown, about nine mill 

 long, and two null, in diameter, closely wrinkled transversely, M'ith the white 

 salivary glands attached to each side ; the digestive gland is liidit brownish- 

 ochre, and forms the hindmost point, but a lobe reaches far forward. ° 



F'=- 231. Fig. 235. Fig. 236. Fig. 237. 



Alimentary canal and Reproductive organs of Arioii circiimscriptus Johnst. and 

 Avion ainhiguus PoUoncra. 



Fig. 234.— Alimentary canal of >!. circumscriftus Johnst. X 3. (Christchurch, Mr. C. A.shfovd). 



Fig. 235. — Reproductive organs of .-^. circtimscriptus Johnst. X 3. (Christchurch, Mr. C. Ashford). 



Fig. 236. — Proximal end of Reproductive organs of A. ambitus X I. Hardonecchia, Piedmont 

 (after Pol I on era). 



Fig. 2.37. — Proximal end of Reproductive organs of A. amhiguus var. armoHcana X 4. Brest, 

 France (after Pollonera). 



_ a.g;. albumen gland ; e/>. epiphallus ; oi. ovotestis ; ffli. oviduct ; s.d. sperm duct ; sp. spermatheca 

 with retractor ; v.d. vas deferens ; z'./. vestibular gland. 



The MANDIBLE or jaw is rather more than a mill, broad, and much resembles 

 that of A. hoHensin in general aspect, but in the 

 particular example was thicker in substance, and of 

 deep brown colour. It is of the usual ciescentic 

 sliape, and strongly arcuate from front to back, with 

 about ten vertical libs or thiclcenings, which strongly 

 denticulate the upper margin, and are more eveiily 

 distributed over tlie whole anterior surface of the 

 jaw than in A. hortensis ; the lower half of the jaw 

 is much more deeply coloured than the top, which is of an amber colour, with the 

 darker ribs very apparent thereon. 



_ The LINGUAL MEAIBRANE is about three mill, long, and about one mill, in 

 width, and composed of about 125 slightly-curved transverse rows of denticles, 

 each row formed by a distinctly tricuspid median tootli, the strong and well- 

 developed mesocone with lateral exjiatisioiis ; the lateral teetli are about seventeen 

 in number, obscurely tricuspid, sliowing a powerful mesocone with lateral expan- 

 sions, an enlarged eetocone, and a more tlian correspondingly reduced endocone, 

 without cutting-point ; the marginals are bicuspid, bearing a strong mesocone and 

 a distinct and pointed eetocone, while the few extreme marginals are ^uite embry- 

 onic in character. 



Fig. 238.— Mandible or jaw ol 

 Avion circuiHscriptus X 20. 

 (Stroud, Mr. E. J. Elliott). 



9 



% 



24 2D. 15 



IJ. 20. 24. 



\7^ 



\f 



F[G. 239. — Representative denticles from a transver'^e row of the Hngnal teeth o{ A. circuniscripius 

 X 180. The animal collected at Stroud by Mr. E. J. Elliott, and the palate prepared by Mr. Neville. 



The dental formula of a Stroud specimen collected liy ^Ir. E. J. Elliott is 



