REPORT ON THE GASTEROPODA. 213 



of Buccinum and Cominella; for, as in the latter, the nucleus is at the lower end, but it 

 is not apical, but is within the edge towards the outer margin as in the former. H. 0'4 in. 

 B. 0-18. Penultimate whorl, height 0"1. Mouth, height 0-19, breadth Oil. 



2. Buccinum (?) aquilarum? Watson (PL XIII. fig. 4). 



Buccinum (?) aquilarum, Watson, Prelim. Report, pt. 13, Journ. Linn. Soc. Lond., vol. xvi. p. 359. 



Station 78. July 10, 1873. Lat. 37° 26' N., long. 25° 13' W. Off San Miguel, 

 Azores. 1000 fathoms. Volcanic mud. 



Shell. — Small, thin, white, ventricose, biconical, oval, subscalar, with an oval, slightly 

 oblique mouth, and a short canal. Sculpture : Longitudinals — on the upper whorls there 

 are many feeble, close-set, straight riblets, which are very faint and merge into the lines 

 of growth on the last whorl. Spirals — on the whole surface, are fine, rounded, spiral 

 threadlets parted by shallow furrows which are broader than the ribs. Colour semi- 

 transparent white, under a thin yellow membranaceous epidermis. Spire short, broad, 

 conical, subscalar. Apex small, but rounded. Wliorls 6, slightly flattened above ; below 

 this there is a very blunt angulation, and the lower part of each whorl is subcylindrical ; 

 the last whorl is ventricose, contracting on the base to a very short, rather lop-sided 

 snout. Suture impressed. Mouth rather large, oval, rounded at the top, and prolonged 

 below into an oblique, short, open canal. Outer lip thin, but not sharp, very bluntly 

 angulated near the top, of regular curve, open, with a very slight basal cut at the point 

 of the pillar. Inner lip : a thick layer of glaze, with a prominent edge continuous with 

 the outer lip, runs down parallel to the belly-margin, and is cut off by the oblique canal 

 at the point of the pillar, which is neither swollen nor thickened. H. 0"33 in. B. 0*21. 

 Penultimate whorl, height 0-07. Mouth, height 0"22, breadth 0-13. 



This is a perplexing form, in general aspect very like several of the Admetes. Than Admete ovata, 

 E. Sm., from Japan, it is very much higher and more attenuated in the spire ; than Admete crispa, 

 Moller, it is much more tumid, and lower in the spire ; than Admete viridula, Fabr., it is more 

 delicately sculptured, is higher in the spire, and is of slower increase. The absence of the generic 

 teeth on the pillar and the presence of the slight basal sinus are both features not without parallel 

 in the genus Admete ; but in all Admetes, so far as known to me, there is a varicose twist at the 

 point of the pillar, between which and the edge of the inner lip lies a more or less distinct umbilical 

 chink or furrow. In this Challenger shell there is no swelling whatever, and scarcely any twist even 

 in the sculpture, and not the slightest approach to an umbilical chink. The absence of the varicose 

 twist is, indeed, rather an objection to putting this species under Buccinum ; but that genus already 

 accommodates forms still more exceptional than the present one. Volutharpa is perhaps nearer ; 

 but I do not sufficiently know the limits of that genus to take liberties with it ; the absence of an 

 operculum, which seems its only positive claim to generic standing, is a feature out of recognition in 

 the present case. 



1 Acor = (vulgo) eagle, whence the name of the islands. 



