Hutton. — On some Branchiate Gastropoda. 125 



Calcar cookii, Chemnitz. PI. XIV., fig. p. 



Dentition. — Central tooth elongated, anterior half with parallel sides, 

 posterior half expanded ; winged on each side near the middle, posterior 

 margin straight ; no cutting-point. First to fourth lateral similar, broad, 

 without cutting-points, with two wings on the exterior side which receive 

 between them the inner side of the next tooth. Fifth lateral with the 

 outer posterior corner produced into a long stalk, the reflexed portion 

 tricuspid. First marginal very large, produced anteriorly and reflected at 

 the margin, a strong triangular cutting-point arising from the middle of 

 the tooth. Marginal teeth with smooth cutting-points. 



The specimen figured was sent from Auckland by Mr. T. F. Cheeseman. 

 The dentition is so very different from that of Calcar imperialis (as figured 

 by Hogg) that the two cannot be placed in the same genus, and the name 

 Calcar cookii will have to be altered to Cookia sulcata, Martyn. 



Diloma jethiops, Grmelin. PI. XV., fig. a. 



Dentition. — Central tooth broader than long, oblique, sloping posteriorly 

 to the left, reflexed portion without cutting-points, but serrated on both 

 sides at the base. Lateral teeth with cutting-points which are denticulated 

 on both sides, those on the outer side being stronger. Outer marginals 

 denticulated on both sides, the inner marginals denticulated on the outer 

 side only. 



The specimen figured was collected at Lyttelton. 



Diloma nigerrima, Chemnitz. PI. XV., fig. b. 



Animal black : head with a narrow transverse band of yellow near 

 the front margin ; rostrum margined with white : tentacles long and taper- 

 ing, longitudinally striped with black and yellowish. Filaments blue-black, 

 three on a side, sometimes a fourth on the left side.* Foot white, closely 

 and finely marbled with blue-black, and broadly margined with yellow 

 veined with black. Dentition. — Central tooth much broader than long, 

 oblique, sloping posteriorly to the right, the reflexed portion serrated on 

 both margins, cutting-points of lateral teeth denticulated on both sides, but 

 more strongly on the outside. Cutting-points of marginal teeth strongly 

 denticulated on both sides. 



The specimen figured was collected at Lyttelton. The movements of 

 this species are very rapid, quite different from those of the other species of 

 the genus. 



Diloma undulosa, Adams. PI. XV., fig. c. 



Animal brownish-black ; rostrum narrowly margined with yellow ; ten- 

 tacles margined with white ; eye-peduncles broad and short ; head-lobes 

 pectinated ; the right side lappet smooth, the left pectinated between the 



* I have noticed the same in D. cethiops. 



