INVERTEBRATE PALAEONTOLOGY. 373 



and conchologists, l)ii( more particularly by the- former, owing to the very 

 great difficulty of classifying, by the shell alone, a wide range of fusiform 

 types. I accept it here, however, nearly in the restricted sense in which it 

 is used by H. and A. Adams, in their important work on the Genera of Recent 

 Mollusca; though I add, provisionally, under a new subgencric name, a fossil 

 type that may possibly represent a distinct genus. 



The sections included, as the genus is here understood, may be severally 

 distinguished as follows : 



1. fusus, Bruguiere (typical, = Colus, Humphrey). 



Shell elongate-fusiform ; spire produced ; volutions provided with 

 carina?, nodes, folds, or costa;, sometimes spiniferons; canal long, 

 slender, and straight. — (Type as above stated.) 



2. serrifusus, Meek. 



Shell short-fusiform ; body-volution large, and hi- or tricarinate, 

 with carinas more or less nodose; spire and canal' moderate, the latter 

 bent and more or less twisted ; outer lip broadly but slightly sinuous 

 in outline, between the upper carina and the suture. — {Fusus Dako- 

 tensis, M. & H.) 



3. sinistralia, H. and A. Adams. 



Shell unsymmetrically-fusiform, sinistral; spire elongated, or 

 more than equaling the length of the aperture and canal, which latter 

 is short, twisted, and bent. — (Fusus elegans, Reeve.) 



A complete revision, however, of the numerous extinct species still 

 ranged under the general name Fusus, by many authors, would doubtless 

 result in the elimination of a portion of them under other names, and the 

 establishment of some new genera and subgenera. This is especially the 

 case with the Cretaceous species, many of which, as elsewhere suggested, 

 will probably, on critical examination, be found, judging from Late experience, 

 to possess plaits far around out of sight on the columella, and consequently 

 have to be ranged in or near the genus Fasciolaria. 



The type for which the subgeneric name Serrifusus is here proposed 

 seems to be entirely destitute of any traces of such plaits on the columella, 

 and in other respects more nearly related to the genus Fusus, though its shorter, 

 bent canal, larger' body-volution, and the somewhat sinuous outline of the 

 upper part of its outer lip, seem to require its separation, at least subge- 



