6 THIRD SUPPLEMENT TO THE CRAG MOLLUSCA. 



on the inside of the outer lip ; but this may be from its not having arrived at maturity. 

 There are "traces of spiral striae, but the specimen has had its surface much eroded, and 

 when perfect it was probably fully covered. It has about a dozen costulas or riblets on 

 the last volution. [The specimen appears to me to be a derivative. ED.] 



COLUMBELLA ERYTHROSTOMA? Bonanni. 3rd Suppt., Tab. 1, fig. 10 a, b. 



COLUMBELLA ERYTHuosTOMA, Bon. Fide Bellardi Monog. delle Columbelle foss. del 



Piedmonte, p. 9, fig. 4, 1848. 



Spec, char. " Testa turrito-elongata, turgidula, anfractibus laembus, convexiusculis ; 

 ultimo magno : apertura dilatato-elongata, labro subarcuato, subvaricoso ; columetta 

 adnata, regulariter et numerose rugosa ; rugis brevibus externis" Bellardi. 



Locality. Red Crag, Butley. 



The above figures represent specimens found by myself some years ago, in the Red 

 Crag of Butley, which I have hitherto left unnoticed, regarding them merely as specimens 

 of C. sulcata, Sowerby, derived from an older part of the Red Crag, and worn smooth in 

 consequence, that species being abundant at Walton, and variable in length ; one figured 

 in Supplement to Crag Moll., p. 9, Tab. 11, f. 16, measuring one inch and five-eighths, 

 while another is less than three-quarters of an inch, both of them being full-grown, and 

 belonging, I believe, to the same species. 



The specimens now figured are quite smooth, a character agreeing with that which 

 Bellardi has given for the Italian fossil erythrostoma, which is described as " anfractibus 

 lavibus ; " but if ray specimens have been derived from an anterior Red Crag bed, they 

 may have lost the spiral striae from either decortication or abrasion, and so be, as I 

 originally supposed them to be, merely worn specimens of C. sulcata. Mr. A. Bell gives 

 three specimens of this genus from what he terms the Middle and Upper Crag, viz. C. 

 sulcata, C. abbreviata, and C. Borsoni ; and another is added in Prof. Prestwich's catalogue 

 of mollusca from the Red Crag, viz. C. scripta. In my original work, and in the supple- 

 ments thereto, I have figured several different forms of what appear all to be C. sulcata ; 

 and as two specimens, which had been furnished him by Mr. A. Bell, under the name of 

 Columbetta abbreviata, have been kindly sent to me by Dr. Reed, I have figured one of 

 them (Tab. 1, fig. 6), in order that a representation of the shell, on the strength of which 

 this name of abbreviata has been introduced into the list of Red Crag Mollusca, may 

 appear. The shorter of the two specimens which I have figured under the name of 

 erythrostoma (fig. 10 A), agrees with this abbreviata, but is smooth. 



