510 



EEV. E. BOOG WATSON OJf THE 



ridges are fewer, and the furrows between much wider and 

 more open. 



3. Dei^TALIUM AMPHIALUM, W. (a//(^ta\os.) 



St. 323. Feb. 28, 1876. Lat. 35° 39' S., long. 50° 47' W. Off 

 the mouth of La Plata. 1900 fms. Grrey mud. 2 specimens. 

 Animal. — Small for the shell, of a pale ruddy colour, which is 

 deeper and browner on the foot and liver, the latter very large : 

 two large masses of long, fine, equal captacula fill the mantle- 

 cavity ; they spring from the front of the pedestal out of which 

 the buccal mass and the foot rise ; and of these, two large 

 bunches project through the mantle-orifice : buccal tentacles 

 very small. 



Shell. — Long, conical, nearly straight, what curve there is very 

 equal throughout, of a dirty brownish yellow, chalky on the 

 surface, porcellanous beneatli. Both specimens are very much 

 eroded, especially on the convex curve, and show a prodigious 

 number of layers of shell, which is, however, thin and slight. 

 There is a short, irregular anal fissure on the convex curve. 

 Sculpture. There are about 50 very sliglitly raised, rounded, 

 longitudinal ridges, the furrows between which are very 

 much like the ridges reversed, being very shallow and open. 

 These vary a good deal at different parts of the shell, and 

 tend to disappear towards the mouth ; they are crossed by 

 fine, close-set, sharp, but very superficial, irregular scratches, 

 which run elliptically round the shell, advancing on the con- 

 cave and retreating on the convex curve. As the shell grows, 

 these lines of growth become harsh and broken. L. 2, nearly. 

 B. 0-3, nearly ; least B. 05. 



This species is somewhat like the D. zelandicum, Sow. " jun., 

 N. Zealand," B.M., but in form is much stumpier, the ridges 

 are closer, and the shell thinner. Than D. grande, Desh., 

 " Japan," B.M., it likewise is stumpier in form, the ridges are less 

 strong, the furrow^s less marked, the circular striae less sharp : 

 in jD. amphiahm the longitudinal ridges die out, while in D. 

 grande they continue equally strong. 



4. DeNTALIUM CEEAS, W. (icepas.) 



St. 246. July 2, 1875. Lat. 36° 10' N., long. 178° 0' E. Mid 

 Pacific, E. of Japan. 2050 fms. Grrey ooze. 3 specimens. 



St. 299. Dec. 14, 1876. Lat. 33° 31' S., long. 74° 48' AV. W. 

 of Yalparaiso. 2160 fms. Grey mud. 1 specimen. 



