396 KEY. E. BOOG WATSON OS THE 



the axial line into a long, narrowish, cylindrical, strong, and 

 slightly reverted snout. Suture a rather minute, sharp, some- 

 what irregular line, which does not at all follow the spiral mark- 

 ings, but crosses these up and down in an unusally irregular 

 manner ; it is well defined by the concave hollow formed by the 

 contraction of the whorls above and below it. Mouth club- 

 shaped, being somewhat angularly ovate above (with a sharpish 

 point at the top and an angulation at the keel), and prolonged 

 below into the somewhat oblique open canal, which is kept open 

 by the oblique cutting away of the pillar. Outer lip sharp, but 

 strong ; it leaves the body at an acute angle and retreats towards 

 the left to form the sinus, which is open and near, but not immedi- 

 ately at the body : from the sinus the lip-edge advances with a 

 strong forward convexity to the point of the canal ; laterally it is 

 also rather convex, but is contracted into the snout, along the 

 edge of which it is pretty straight with a somewhat oblique 

 direction towards the left, and here it is patulous. .Tuner Up 

 porcellanous, smooth, narrow, cut off, and slightly twisted in 

 front, and running out at the point to a sharp edge along the 

 canal, the point of which is then rounded and patulous. H. I'd. 

 B. 0-5. Penultimate whorl, height 0"23. Mouth, total length 07, 

 breadth 023. 



In this species the generic sinus lies high and is open, which 

 reduces to rather small dimensions the little testaceous shelf 

 which forms its upper edge and separates it from the body-whorl; 

 but the sinus does not, as in Defrancia, lie quite at the upper 

 angle of the mouth. The shell has some resemblance to P. nodi- 

 fera, Lam., from China and the Philippines ; but in that species the 

 body-whorl is much more tumid, the canal is much longer and is 

 more bent to the left, the apex is more uninterruptedly conical, 

 the suture is deeper, the spiral threads are not so universal and 

 are in their course regular. In texture this species is very much 

 like P. nivalis, Loven. 



7. PlettROTOMA (StTRCUI/A) SYNGENES, n. sp. (avyyevi]S, 

 allied.) 



St. 23. March 15, 1873. Lat. 18° 24' N., long. 63° 28' W. 

 Sombrero Island, off St. Thomas, Dan. W. Indies. 450 fms. 

 Glohifferina-ooze. 



St. 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 20" W. 

 Culebra Island, off St. Thomas, Dan. W. Indies. 390 fms. Coral- 

 mud. 



