MUSEUM OF COMPARATIVE ZOOLOGY. 81 



to twenty-four (on the terminal) on each whorl ; apex wanting, width of shell 

 at fracture 1.75 ram.; transverse sculpture consisting solely of the lines of 

 growth, which, on the last whorl, occasionally rise to the dignity of faint plica- 

 tions ; spiral sculpture consisting of the three rows of tubercles above men- 

 tioned, of which the anterior is slightly the most prominent and the middle 

 row slightly the most pointed ; these tubercles are connected by a slightly 

 raised band, often obsolete and never very distinct, somewhat narrower than 

 the tubercles, and strongest on the last whorl ; in addition to these the ba 

 the whorl at its periphery is ornamented by a plain, raised, narrow band, be- 

 hind which is a rather deep narrow groove, and immediately in front of which 

 is the suture, which would otherwise be hardly visible ; about three raised 

 lines separated by shallow grooves are found on the base of the shell toward its 

 outer part, the inner line faintest, and the vicinity of the canal without spiral 

 sculpture ; basal surface in the adult flattened before the aperture, rounded 

 behind it, on the whole more rounded than in most species ; canal short, 

 slightly recurved, possibly entire in old shells, but in the specimens at hand 

 open in front ; sutural aperture large, rounded, with reflected edges, probably 

 finally closed in front ; outer lip chipped, but evidently produced and bent in 

 toward the pillar ; a slight callus on the body whorl and pillar ; aperture 

 roundly obliquely rhomboidal. Lon. of shell (decapitated), 26.0 ; of first 

 whorl at fracture, 0.75 ; of last whorl, 4.0; all measured along the axis. Lon. of 

 aperture, 3.0; lat of do., 1.75 ; of last whorl, 3.25 mm. Defl. about 10°. 



This is probably the largest and most elongated species of the group. All 

 the specimens were decapitated, but fresh. The characters do not agree with 

 any of those species described by Hinds, D'Orbigny, or Watson, and are suffi- 

 ciently well marked when full grown to distinguish it at a glance from any of 

 the other species. In the absence of the tip the flattened whorls give it a 

 tubular aspect. 



Triforis turris-thomee D'Orbigny. 



CcrUhittm turris-thomoe D'Orbigny, Sagra, Moll. Cub., II. p. 155, Atlas, PI. XXIII. 



figs. 10-12, 1853. 



Station 2, 805 fms., one dead specimen, probably drifted From shoaler water. 

 Reported by D'Orbigny in shell sand from Cuba and Guadaloupe Island. 



Triforis bigemma Watson. 

 Ceritliiwm (Triforis) bigemma Watson, Joum. Linn. Soc., XV. p. 101, 1SS0. 

 St. Thomas, W. I., 390 fms.) 

 Yucatan Strait, 640 fms. 



Triforis inflatum Watson. 



CeritMum [Triforis) inflation Watson, toe. a'/., p. 103. 



Bame localities as the preceding. 



voi,. ix. — no. 2. 8 



