handles: anatomy of acatus. 105 



(e) Var. roseolabiata (Pfr. & Novill). "Animal light chocolate, 

 tentacles paler with orange bulbs. Exactly resembling A. superb as 

 var. Grevillei, having also the same habitat." 



4. Acavus Waltoni (Rv.). 



" Animal bluish-black, tentacles grey. Peristome very dark brown 

 or black. 



Ilab. — Among fallen leaves in forest, Ambagamuwa. Common 

 throughout the Central Province. 2000-4000 ft." 



5. Acavus Skinneri (Rv.). 



"Animal bluish-grey all over, tentacles grey. Peristome varies 

 from pale brown to deep violet. 



ZZfli.— Haputala forests (5000-6000 ft.). Amongst fallen leaves." 

 Pattipola, province of Uva, 5000 ft. (Haly). 1 



6. Acavus Poleii, Collett. 



" Animal mouse-colour, head and tentacles paler. Peristome always 

 white. 



Sab. — Udagama, Southern Province. 500 ft. On decaying logs 

 in the forest swamps. A low-country shell." 



The shell of this species is frequently covered with alga) like the 

 A. heemastomus type. This alga is never found on the shells of 

 A. Waltoni and A. Skinneri. 



Internal Anatomy of Acavus. 



The Alimentary Canal (PI. IX, Fig. 1). The macroscopic features 

 and general arrangement of the alimentary canal very closely 

 resemble the condition obtaining in Selix aspersa, Mull. The jaw 

 is of the oxygnath type, strong, arcuate, perfectly smooth, without 

 median or lateral projections. The buccal mass (b.m.) is very 

 muscular, and the radula-sac well developed. The oesophagus (o.) 

 arises from the anterior dorsal surface of the buccal mass, and after 

 .passing through the nerve-ring, becomes slightly enlarged to form 

 a crop : closely enveloping this structure are a pair of very compact 

 salivary glands (s.g.), which show a tendency to fuse at their anterior 

 extremities. Two fine salivary ducts run forward alongside the 

 oesophagus and convey the glandular secretion to the pharynx. The 

 stomach (st.) is a large structure bounded by the right and left lobes 

 of the liver, and partially divided into two chambers — a thin-walled 

 portion into which the oesophagus opens, and a thicker- walled chamber 

 receiving the right and left bile-ducts from the corresponding lobes 

 of the liver. The intestine («'.) lies imbedded in the left lobe of the 

 liver and follows a course similar to that in Selix. The rectum (;•.), 



O. Collett : " Contributions to Ceylon Malacology : (2) Description of a new 

 Helicoid Land Shell from the Southern Province": Journ. Ceylon Branch 

 Roy. Asiatic Soc, vol. xv, No. 49, reprint, p. 2. 



