Hurron.—On some Branchiate Gastropoda. 125 
Carcar coox, Chemnitz. Pl. XIV., fig. r. 
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. 
Doma zrHioPs, Gmelin. Pl. 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. Pl. 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. 
Ditoma UNDULOSA, Adams. Pl. XV., fig. c. 
Animal brownish-black; rostrum narrowly margined with yellow ; ten- 
 tacles margined with white; eye-peduncles broad and short; head-lobes 
* I have noticed the same in D. ethiops. 
