A. FE. Verrill— Catalogue of Marine Mollusea. 461 
Bela incisula Verrill, sp. nov. 
? Pleurotoma Trevelyana, var. Smithii Jeffreys, Ann. and Mag. Nat. Hist., 1876, p. 
332. 
Bela impressa ? Verrill, Proce. U.S. Nat. Mus., iii, pp. 365, 1880, (non Morch.) 
PuLareE XLII, rigure 12. Puare LVI, FIGURE 14. 
The shell is small, sub-fusiform, to short ovate, with about five or 
six turreted, flattened whorls, which are angularly shouldered just 
below the suture. The subsutural band arises abruptly from the 
suture, nearly at right angles, and its surface is flat or slightly con- 
save, marked by strongly recurved lines of growth, but mostly 
? 
without spiral lines. The shoulder is often nearly right-angled. The 
whorls are decidedly flattened in the middle. There are on the last 
whorl, about twenty rather broad, flattened or rounded ribs, which 
are nearly straight, a little prominent and usually slightly nodose at 
the shoulder, but they disappear a short distance below it. They 
are separated by well excavated, concave grooves, deepest close to 
the shoulder. 
The most characteristic feature of the sculpture is that the surface 
is marked by rather fine, but regular and distinct, sharply incised, 
narrow, revolving grooves, which are rather distant, with flat inter- 
vals. Of these there are usually about three to five on the penulti- 
mate whorl, and about twenty to twenty-eight on the last, the 
greater number being below the middle, on the siphon, where they 
become coarser and closer, with narrower rounded intervals. One of 
the sulci, just below the shoulder, is usually more distinct, and cuts 
the ribs so as to give their upper ends a subnodulous appearance ; 
below this there is usually a rather wide zone, without grooves ; 
usually no revolving lines above the shoulder, The apex is usually 
eroded ; when perfect it is acute. The nucleus has a very small and 
slightly prominent smooth apex ; its first turn is marked with fine 
spiral lines; the next whorl has, at first, about three stronger, spiral, 
raised cinguli, which soon begin to be crossed by thin transverse 
riblets, 
Aperture about half the length of the shell, narrow ovate, or 
elliptical, angulated above. Canal short, nearly straight, a little nar- 
rowed at the base by an incurvature of the lip. The outer lip has a 
decided angle at the shoulder, below which the edge is well-rounded, 
and projects strongly forward, in the middle; the sinus, above the 
shoulder, is rather deep, wide, and eyenly rounded within, Colu- 
