164 Transactions. — Zoology. 



The first lateral is somewhat triangular in shape, its breadth being three 

 times its height ; the reflected portion is denticulated on the margin, and 

 there is a large cutting point at the inner end, with a small one inside it. 

 The second and third laterals are nearly similar, the apices are blunt and 

 denticulated ; the outer margin is denticulated in both, while the third 

 lateral has also some denticulations on the inner margin. (PI. YII., 

 fig. A.) 



LiTTOEiNA ciNCTA. Animal. Foot sooty brown ; head brownish black, 

 with a white space round the eye ; tentacles brownish black with white tips, 

 and a white triangular mark at the base. 



Dentition. Eadula very long ; -01 inch in breadth. Central tooth -002 

 inch in length, with a rounded cutting point. The first lateral has two 

 large cutting points ; the second lateral has four, and the third lateral five 

 cutting points. The length of the third lateral is "004 inch. (PI. VII., 

 fig. D.) The drawings were made from a specimen from Sumner, the axis 

 of which was -43 inch. The operculum is sub-sphal, the nucleus near the 

 end. 



This species varies very much in colour. 



LiTTORiNA ciERULESCENS. Animal and operculum as in L. cincta. The 

 dentition is smaller than in L. cincta, and the cutting points finer. In a 

 specimen with an axis of -42 inch, the length of the central tooth was -015 

 inch, and that of the third lateral -025 inch. Breadth of radula, "006 

 inch. (PI. VII., fig. E.) According to Mr. Gwyn Jeffreys, this species is 

 identical with L. neritoides, Lin. 



FossARiNA vARius. Animal. Foot white, simple and truncated in front ; 

 head dark purple black, with a reddish tinge on each side of the neck ; 

 rostrum short, tipped with yellow ; tentacles moderate with the eyes at 

 their outer bases, white irregularly ringed with black. Dentition. This 

 much resembles that of Littorina, but the third lateral tooth is not broad at 

 the apex, and the radula is short. (PI. VII., fig. b.) The radula is -005 in 

 breadth. The operculum is subspiral, with the nucleus central. (PI. VII., 

 fig. c.) 



This species is common at Sumner, associated with L. chicta and L. 

 ccerulescens, on the rocks, above low-water mark. 



Janthina communis. The radula has numerous aculeate teeth, which 

 decrease in size towards the anterior end ; they do not seem to be arranged 

 in transverse rows. The teeth have a simple hooked apex, and a slightly 

 expanded emarginate base. The length of a posterior tooth is -03 inch, 

 that of an anterior tooth is -008 inch. (PI. VII., fig. f.) 



The specimen was given me by the Hon. G. McLean, who captured it 

 in a towing net off the coast of the North Island, 



