514 BET. R. BOOG WATSON ON THE 



Shell. — Very long and narrow, very sliglitly bent, and that almost 



entirely above ; a very little flattened on tbe concave curve so 



as to be slightly trigonal ; white, opaquely porcellanous, a little 



glossy, not thick but strong. Sculpture. Closely and regularly 



girt round elliptically with scratch-like puckerings in the lines 



of growth, of which there are about 55 in the yV ^^ ^^ 



inch. Longitudinally striped with fine ribs, of which there are 



from 17 to 20, sharp and well defined bj^ still broader furrows 



toward the apex, but down the shell these increase in number 



and steadily decrease in definiteness till they only show as a 



feeble system of lines on the rounded surface. At the apex 



there is on the convex curve a ragged irregular fissure about 



0-1 in. long. L. 1'93. B. at mouth 0-13, at apex 0-02. 



As compared with D. semipolifum, Sow., this is a longer, 



straighter, more attenuated shell, with striae stronger, blunter, 



and more persistent. It is not unlike D. antillarum, D'Orb., in 



texture and in size, but is much straighter and narrower, and the 



early ribs are much finer and fewer. It is intermediate in form 



between D. erectum, Gr. B. Sow., and D. splendidum, Desh., a 



little stumpier and more curved than the first and less so than the 



second ; it is much mOre longitudinally ribbed and less polished 



than either. Than B. Lessoni, Desh., it is much more attenuated 



and never so strongly ribbed longitudinally. Than D. inversum, 



Desh., it is more strongly and persistently striate longitudinally. 



The young shell is perplexingly like that of B. entails, var. 



orthrum, W., but is a little straighter, broadens more slowly, and 



the ribs project more sharply. In maturer specimens this species 



is obviously much more attenuated than the former. 



9. Dentalium acutissimum, W. 



St. 218. Mar. 1, 1875. Lat. 2° 33' S., long. 144° 4' E. N. 



of Papua. 1070 fms. Glohiqerina-ooze. 2 specimens. 



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



Pacific, E. of Japan. 2050 fms. Grrey ooze. 1 specimen. 



Shell. — Long and very attenuated, rather straight, the curve very 

 regular, very thin, brilliant, and glassy. Sculpture. The sur- 

 face is cro?sed by very fine sharpish irregular striee, which run 

 very elliptically round. In the young shell the surface is 

 very regularly and finely scratched by a great number of close- 



