514 



HEV. R. BOOG WATSON ON THE 



Shell. — Yery long and narrow, very slightly bent, and that almost 

 entirely above ; a very little flattened on the 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 whicli 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 b^ 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 

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

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

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

 and more persistent. It is not unlike B. 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. erectiim, G. 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. entalis, 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' R N. 



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



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



Pacific, E. of Japan. 2050 fms. G-rey ooze. 1 specimen. 



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

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

 face is crossed by very fine sharpish irregular striae, which run 

 very elliptically round. In the young shell the surface is 

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



