REPORT ON THE GASTEROPODA. 343 



conical, scalar, in consequence of the drooping projecting shoulder at the top of each 

 whorl. Apex consists of 3j embryonic whorls, which are conically globose, smooth, 

 keeled, closely, roundedly ribbed, with a deepish suture, and rise to a minute point (crushed). 

 Whorls 8^ in all, a little bunchy and disorderly ; they have a long slightly drooping 

 shoulder defined by the keel, below which they are cylindrical, with a slight contraction 

 into the lower suture ; the last whorl is small, with a contracting scarcely convex base, 

 prolonged into a small, but distinct, and somewhat cylindrical snout. Suture small, slightly 

 impressed. Mouth small, narrow, slightly pear-shaped, oblique, triangular above, prolonged 

 into the small canal below. Outer lip flat at the shoulder, angulated at the keel, slightly 

 convex below this ; the edge projects thinly beyond the last longitudinal rib, which serves 

 as a varix : it presents a flattened, but regular curve from the point of the shell to the 

 keel, where the edge forms a little shoulder, between which and the body lies the narrow 

 round small sinus, with its flanged border. Inner lip straight, with a very thin narrow 

 glaze which early runs out to the rim, being cut off by the slightly oblique and twisted 

 edge, which continues with a slight patulous margin to the point of the shell. H. 0*34 

 in. B. 0-12. Penultimate whorl, height 0'07. Mouth, height (P15, breadth 0-04. 



The specimen from Station 75 is somewhat broken and rubbed, and is therefore attributed to this 

 species with a doubt ; the identity, so far as means of comparison exist, is close, only the individual 

 whorls are a little broader and shorter. Pleurotoma (ftfangelia) corallina, Watson, is so similar, that 

 I classed this at first as a variety of that other under the name elongata ; but I am now persuaded 

 of their distinctness. In Pleurotoma acanthodes the embryonic apex is narrower, higher, and sharper, 

 with an indefinite junction to the regular whorls ; in Pleurotoma corallina it is much more compact, 

 with the whorls more sunken or immersed, broader, and lower, and its junction is very distinctly 

 defined. In Pleurotoma acanthodes there are 3^ embryonic whorls, which are contracted, also 

 minutely tubercled on the keel ; and the lower part of the whorls is nearly smooth. In Pleurotoma 

 corallina there are 4 embryonic whorls, which are not keeled and are scarcely angulated, with a very 

 slight contraction into the lower suture ; the riblets are stronger, and extend from the upper almost 

 to the lower suture. Pleurotoma corallina is a larger, sharper-cut shell, squarer in its lines ; four 

 whorls in it are as long as five in the other, the body-whorl especially being longer and in the base 

 much more elongated and fuller, and the snout is broader. 



74. Pleurotoma (Mangelia) corallina, Watson (PI. XXIII. fig. 1). 



Pleurotoma (Mangelia) corallina, Watson, Prelim. Report., pt. 9, Journ. Linn. Soc. Lond., voL xv. 



p. 435. 



Station 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 30" W. North of 

 Culebra Island, West Indies. 390 fathoms. Pteropod ooze. 



Shell. — High, narrow, with squarish lines, biconical, ribbed and spiralled, of a frosted- 

 white colour and coral-like texture, with a scalar, blunt, but small-pointed spire, a smallish 



