30 RET. -R. BOOG WATSOIST OK THE 



the first, so that toward tlie margia 100 to 130 can be counted. 

 The one in continuation of the generic puncture is slightly raised, 

 double, and partially split, especially above, giving the imj)ressiou 

 of a suture ; these are crossed by concentric threads of almost 

 equal strength v^ith the ribs, in crossing which they rise into 

 knots which sharply roughen the surface. Colour brownish grey, 

 but the specimen is somewhat blackened and discoloured*. Apex 

 a good deal depressed, curled-in and projected backwards exactly 

 in the middle line of the shell, the minute tip just standing out 

 on the right, forming a spire of 2^ whorls. SUt very low, having 

 its centre quite two thirds down the front slope ; it is lanceolate, 

 square behind, broadening, a little irregularly, in the middle, and 

 slowly contracting to a small narrow point in front : the old scar 

 is a shallow furrow with sharp sides ; and the bottom is scored 

 across with old edge-lines. Margin thin, toothed, and crimped 

 on the edges by the ribs. Inside porcellaneous, somewhat in- 

 dented on the line of the ribs ; the apex is deeply hollowed, a 

 deepening and widening groove extends from the margin to the 

 slit, Avhich is shortly covered by the regularly curved, strong, 

 unbuttressed septum. L. O'S. B. 0-62. H. 0-32. 



My own observations entirely confirm the remarks of Mr. "W. 

 H. Dall ('Blake' Dredgiugs, Bull. Mus. Comp. Zool. Harvard 

 Coll. vol. IX. p. 70), that the presence or absence of buttresses to 

 the septum is a feature that cannot be taken as a basis of distinc- 

 tion, since it is not constant in the same species. 



In descriptions of species under this genus a good deal of con- 

 fusion would be avoided if it were remembered that the fissure 

 lies in front of, not behind, the apex. The whole of Grould's de- 

 scriptions of Bimiaa (U.S. Expl. Exped., Moll. pp. 368-372, 

 figs. 475-478) apply to this genus — a fact one would hardly recog- 

 nize from his figures of the animals, in which the tentacles are 

 represented of extreme length and fineness. 



The ' Challenger ' species is exceptionally large. In outline it 

 somewhat resembles Bimula cognata, Gould. My remembrance 

 of this species is that it is quite small ; but Grould figures it large, 

 and gives no indication of size beyond saying that it is small. 

 Functurella craticia further difters from it in being much rounder 

 and lower, with a more depressed and reverted apex, and a slit 

 much more remote from the top. 



* The colour of living specimens from the Bay of Biscay proves to be very 

 much the same. 



