GASTEROPODA. 33 



Locality. Cor. Crag, Gedgrave. 



Red Crag, Sutton. Recent, Mediterranean. 



When my Catalogue was compiled I possessed but two or three specimens from 

 the Red Crag, and those not in very good condition. A few have lately been obtained 

 from the Coralline Crag, at Gedgrave., by Mr. Daniels and myself. These are in better 

 preservation, and sufficiently perfect to bear a fair comparison, and may be considered 

 as identical with the recent species from the Mediterranean. They appear to be the 

 same as the Sue. elegans of Dujardin, some specimens of which, from Touraine, 

 were given to me by Mr. Lyell. It is different from the figure of B. prismaticum, Broc., 

 Table v, fig. 7, as pointed out by Philippi. 



10. NASSA RETICOSA. /. Sow, Tab. Ill, fig. 10, a h. 



NASSA RETICOSA, var. a. VULGARIS. 8. Wood. t. 3, fig. 10, a. 



var. b. HUGOS A 10, b. 



var. c. ELONGATA 10, c. 



var. d. THIARA 10, d. 



var. e. FENESTRALIS - 10, e. 



var./. DEFORMIS - 10, /. 



var. g. CONCINNA - 10, g. 



var. h. COSTATA 10, h. 



var. i. PERVERSA, t. 19, fig. 13, a b. 

 BUCCINUM RETICOSTJM. J. Sow. Min. Conch, t. 110, fig. 2, 1815. 



RUGOSUM 110, fig. 3. 



ELONGATUM - 110, fig. 1. 



Nyst. Coq. foss. de Belg. p. 575, pi. 45, fig. 1, 1844. 

 var. a. 45, fig. 2. 



var. b. - 45, fig. 3. 



Dale. Hist, and Antiq. of Harwich, pi. 10, fig. 12, 1730. 



JV. Testa elongatd, costatd, reticulatd, rugosd, granulatd, striatd vel sulcatd; spird 

 elevatd, aliquando brevi ; aperturd ovatd ; basi reflexd, emarginatd ; labro intus denticulate. 



Shell very variable, sometimes costated, rugose, granulated, reticulated, striated, 

 or sulcated ; spire generally elevated ; aperture ovate, with a short emarginate 

 reflected base ; outer lip denticulated within. 



Locality. Red Crag, passim. 



This is one of the most abundant shells in the Red Crag, and specimens of one or 

 more of the varieties may be procured wherever a section of that formation is visible. 

 B. reticosum, Sow., is here considered as the type of the species, as they are all more or 

 less reticulated, and not all elongated. In some of the varieties the outer lip is thick- 

 ened and denticulated within, while, in others, it is thin and plain. I have not been 

 able to identify N. reticulata with any of these varieties, and have not as yet seen 

 an undoubted specimen of that species from any of the three divisions of the 

 Crag formation. 



The duration of its existence appears to have been limited to the Red Crag period, 



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