82 BULLETIN OF THE 



which empties close to the radula, here seemed to enter the oesophagus some 

 distance behind the proboscis, and I could not find any radular sac at the right 

 side of the proboscis where it should be. On dissolving the whole buccal 

 apparatus in boiling caustic potash, the residue afforded no trace of any teeth. 

 Still I do not feel entirely confident that the animal is normally edentulous, 

 or, if it is, that the gland in question is more than salivary. It would seem 

 absurd that an edentulous mollusk should have a venom-gland. If it is eden- 

 tulous, probably it is capable, in the fanged species, of producing a modified 

 and poisonous secretion, while in others it is merely salivary. 



A related species is Genota atractoides Watson, from the Philippines; it is 

 lighter colored and the details of sculpture are different and stronger than in 

 our species. 



It will be observed that the soft parts are not like those of Conus. The soft 

 parts of Adanson's Genot are not figured by him, nor described except by saying 

 that they resemble those of the Cones. Unless G. mitriformis Wood, and G. 

 papalis Reeve, Adams's types, be different from the present species, it is evident 

 that Genota can rank only as a subdivision of Pleurotoma, and not as a genus 

 by itself. If they do differ, the present forms must be separated as a subgenus 

 of Pleurotoma under Bellardi's name. 



Genus DttiiXIA Gray. 



The species of this group are so varied in their characters, and yet so closely 

 connected by intermediate forms, that at present no absolute conclusions as 

 to their arrangement can be drawn. I shall for convenience separate those 

 here treated of into three groups: A, comprising those with rough sculpture, 

 the spiral sculpture being present and usually emphasized ; B, nearly smooth 

 species with strong transverse ribs, and usually colored, the spiral sculpture 

 faint or absent ; and C, white, polished species, without spiral sculpture, and 

 usually with the spire particularly long in comparison with the rest of the 

 shell. These* are deep-water forms, and shine with a peculiar lustre like rock 

 candy. This is a character shared by several other groups of deep-water 

 shells, and undoubtedly appears in response to some unknown factor in the 

 environment. 



Section A. Roughly sculptured species. 



Drillia ostrearum Stearns. 



Drillia ostrearum Stearns, Proc. Boat. Soc. Nat. Hist., XV. p. 22, 1872. Tryon, 

 Man., VI. p. 197, pi. xxxiv. fig. 79, 1884. 



Habitat. Off Sombrero, in 54-72 fms.; Station 142, Flannagan's Passage, 

 in 27 fms. ; Station 247, near Grenada, in 170 fms. ; Station 272, in 76 fms., off 

 Barbados. Living, in 15 fms. to low- water mark, from Cape Hatteras to Cape 



