OP MOLLUSCA. 197 



6. B. Columni, t. 59. f. 1. 



7. B. Hydatinella, t. 60*. f. 3. 



3. Haminea. 



Head disk large, elongate, naked behind. Eyes subcentral. 

 Mantle edge reflexed on shell behind. Foot elongate ; sides ex- 

 panded, reflexed on shell. Shell ovate, thin, horny, striated ; spire 

 very small, sunken. 



1. H. hydatis?, t. 60. f. l,-2, t. 60*. f. 2. 



2. H. ?, t. 132. f. 4. 



3. H.? ?, t. 178. f. 5. 



4. H. hydatis, Forbes 8f Hartley, B.M. t. Q.Q. f. 3. 



Teeth of Haminea hydatis in very numerous longitudinal series, 

 of uniform similar conical acute glassy teeth in close angular cross 

 series. 



" The branchial plume of Bulla hydatis is a single, regular, crescent- 

 shaped plume of 18 or 20 short, coarse strands, having the artery in 

 the centre, lying in a crypt transversely between the vulva and the 

 anus, floating free, except where under the mantle it is fixed to its 

 roof and to the back of the animal. The heart is at the base of the 

 branchiae." — Clark, Moll. p. 280. 



Fam. V. AMPLUSTRID.E. 



Teeth : central none ; lateral numerous, uniform. Frontal disk 

 produced into ear-like tentacular lobes. Front of aperture of shell 

 more or less channeled. Operculum none. 



1. Amplustrum. 



Shell ovate, imperforated, solid, smooth ; spire distinct, conical, 

 blunt ; aperture oblong, with a broad canal in front. 



1. A. apkistre, t. 59. f. 2, t. 175. f. 1. 



2. BULLINULA. 



Shell ovate, solid, perforated, transversely grooved and dotted; 

 spire conical, blunt ; aperture linear, ovate, broadly channeled in 

 front. 



1. B. undata, t. 59. f. 6. 



2. B. ?, t. 132. f. 5. 



3. Hydatina. 



Shell involute, ovate, thin ; ' axis perforated ; spire flattened ; aper- 

 ture entire in front. 

 1. H. Physis, t. 59. f. 7, t. 175. f. 2, 3, t. 262. f. 1. 



