822 SCAPHOPODA. [Dentalium. 



Length, 19 mm. ; diameter of aperture, 2-5 mm. ; diameter of 

 apex, 0-75 mm. Tube Length, 1mm.; diameter, 0-4 mm. My 

 largest specimen has a length of 28 mm. 



Type in my collection. 



Hob. Port. Pegasus. Stewart Island, in 18 fathoms (Captain 

 Bollons). 



Fam. SIPHONODENTALinXEI, Pilsbry. 

 Siphonopoda, Sars. Gadilince, Stoliczka. Siphonopodidce, Simroth. 



Scaphopoda having the foot either expanded distally in a sym- 

 metrical disc with crenate continuous edge, with or without a median 

 finger-like projection, or simple and vermiform, without developed 

 lateral processes. 



The shell is small and generally smooth, often contracted towards 

 the mouth. 



Distribution. All seas, almost exclusively in deep water. 



Genus 1. CADULUS, Philippi 1844. 



Gadulus, Phil., Enum. Moll. Sicilise, ii, 1844, 209. Type Dentalium 

 ovulum, Philippi. 



Shell tubular, circular or oval in section ; somewhat arcuate ; 

 varying from cask-shaped to acicular ; more or less bulging or swollen 

 near the middle or above, contracting toward the aperture : surface 

 smooth or delicately striated. 



Sect. 1. GADILA, Gray, 1847. 



Gadila, Gray, P.Z.S., 1847, 159. Type : Defaliun> gadus, Mont. Gadus, 

 Montagu. ? Rang, 1829 ; not of Linne. Ditrupa, Gabb ; not of Berkeley. 

 Helonyx, Stimpson, 1865. 



Shell decidedly curved, the general contour convex ventrally, con- 

 cave dorsally ; more or less swollen near the middle or toward the 

 aperture, more tapering toward the apex ; apical orifice not con- 

 tracted by a callous ring, or with the callus far within and weak : 



edges not slit. 



KEY TO SPECIES. 



A. Shell considerably sv, -oili-n near the broader end . . colubridens. 



K Shell not much swollen, contracted near the aperture when adult. 



a. Shell with annular grooves or lines ; length, 5-5 mm. . . spntus. 



an. Shell without annular grooves, with microscopic growth-lines 



only : length, 12 mm. . . ddicatulus. 



\. Cadulus colubridens, Watson, 1879. Plate 32, fig. 6. 



Cadulus colubridens, Watson, J.L.S., xiv, 523 ; Chall. Rep., xv, 18, pi. 3, f. 1 : 

 Man. Conch. (1), xvii, 184, pi. 20, f. 71. 



Shell like an adder's fang, long, sharp, bent, very slightly flattened, 

 swollen near the broader end. The swell, which is faintly angulated 

 and is at one-fourth of the length, is chiefly on the convex curve, but 



