172 PLEUROTOMA. 



relationship with jubata, Hinds. The chief differences are the 

 narrower form, larger tubercles and shorter canal." As jubata 

 is known to vary considerably in the above characters, acuti- 

 gemmata had better be considered a synonym. 



P. EMENDATA, Monterosato. PL 4, fig. 47. 



Shell brown, the spire-whorls with three cingulae and two liraa, 

 the last whorl spirally multicingulate and longitudinally lirulate ; 

 suture slightly but distinctly incised; aperture white within, 

 canal short and wide, sinus wide, between the first and second 

 carina. L. 9, diam. 3 mill. 



Mediterranean Sea; Bay of Biscay, at great depths. 



Mr. Jeffreys says this species inhabits the Japanese Seas ; if 

 so, some of the foregoing species will probably refer to it. 

 Described and figured by Philippi as P. Renieri, Scacchi an 

 erroneous identification and name changed by Monterosato, as 

 above. 



P. NIPONICA, E. A. Smith. PI. 3, fig. 27. 



Shell light brown, whorls six and a-half, the nucleus large, 

 globose, glassy, whorls strongly keeled, and concave above, 

 with two or three fine spiral lirae ; also concave below the carina, 

 and encircled on the bod3 T -whorl by about ten lirae, becoming 

 finer towards the base, the interstices crossed by elevated, 

 oblique growth-striae ; slit in the concavity above the principal 

 carination ; columella a little prominent in the middle and 

 oblique below ; canal short, scarcely recurved. 



L. 7, diam. 2'5 mill. 



Japan. 



The oblique incremental striae are flexuous and turned to the 

 right above the carina, and straight, inclined to the left below it. 



P. TRIPORCATA, E. A. Smith. PL 3, fig. 28. 



Shell pale brown or luteons, the nuclear whorl globular, glassy, 

 the rest encircled by distinct keels, of which there are three on 

 those of the spire, more numerous on the body-whorl; the inter- 

 stices each latticed by three or four revolving lines and incre- 

 mental striae ; notch deep and wide, above the principal keel. 



L. 14, diam. 4*5 mill. 



Japan. 



