18 SECOND SUPPLEMENT TO THE CRAG MOLLUSC A. 



PLEUROTOMA TERES ? Forbes. 2nd Sup., Tab. II, fig. 7, a, 6. 



PLEUROTOMA TERES, Forbes. Ann. and Mag. Nat. Hist., vol. xiv, p. 412, pi. x, fig. 3. 

 MANGELIA TERES, Forbes and Hanb. Brit. Moll., vol. iii, pi. cxiii, figs. 1, 2. 

 DEFRANCIA TERES, Jeff. Brit. Conch., vol. iv, p. 362, pi. Ixxxviii, fig. 5. 



Axis, i^-ths of an inch. 



Locality. Cor. Crag, Sutton. 



A small and worn specimen was found by myself some years ago in the Cor. Crag 

 of Sutton, which I have kept unfigured in the hope of obtaining another and better 

 preserved specimen to assist in its correct determination, but without success. I now 

 give it as above, but with a mark of doubt ; and it is evidently distinct from tereoides, 

 ' Supplement to Crag Moll.,' Addendum Plate, tig. 3 a, b. In the ' Crag Moll./ vol. i, 

 tab. vi, fig. 6, is figured a minute shell with a peculiar ornamentation on the young or 

 upper volutions ; this was called Trophon pautulum, and considered as the young of 

 a larger shell. In Professor Prestwich's paper, ' Quart. Journ. Geol. Soc.,' vol. xxvii, 

 p. 146, this is referred to PL feres, which probably it is (see 1st Supplement to Crag 

 Moll./ p. 27). My present specimen is somewhat abraded, and shows more numerous 

 and close spiral striae than the recent feres usually presents. These in my specimen are 

 not carried over the ribs, but this may be due to obliteration from wear ; the ribs also are 

 more prominent than in the recent shell. On the other hand, the form of the shell, 

 and its deep and broad sinus, agree with the recent species. The striae on the lower 

 whorls are rather more numerous than represented by the engraver. 



PLEUROTOMA GRACILI-COSTATA, 8. Wood. 2nd Sup., Tab. II, fig. 8. 



Spec. Char. Testa ovato-fusiformi, ventricosd, brevispird, acuminatd ; anfractibus 

 vonvexis, longitudinaliter et anguste costatis ; transversim striatis ; ultimo basi sulcato ; 

 columelld canalique brevi, contortis ; aperturd ovatd. 



Axis, f ths of an inch. 



Locality. Cor. Crag, Sutton. 



The specimen figured was found by myself many years ago, but from its peculiar 

 appearance I postponed noticing it, hoping that something better might turn up to 

 assist in its determination. It occurred to me that the costae or ribs which are 

 formed by the periodical arrest of the outer lip during growth might have been originally 



