TRITON WOODII. 121 



costae, with an occasional varix, the costae being prominent on the npper whorls 

 bnt less so toAvartls the base of the shell, crossed by well-marked but irregular 

 spiral ribs of unequal size and nodulous, especially where they intersect the varices 

 and the longitudinal costations ; mouth subquadrate, with a narrow and nearly 

 straight canal ; outer lip thickened by the labial rib, strongly denticulate within ; 

 inner lip rugose. 



Dimensions. — L. 25 mm. B. 14 mm. 



Bisfrihatiov. — Not known living. 



Fossil : Lenham Beds. Waltonian Crag : Little Oakley (probably 

 derivative). 



Northern Italy — Upper Miocene : Sta. Agata. Upper Pliocene : Asti (abun- 

 dant). Pliocene : Rhone valley. 



RemarJcs. — In his Monograph of 1848 (tab. iv, fig. 8), Wood figured a specimen 

 from the Coralline Crag of Gedgrave under the above name, which to some extent 

 resembles the present species in form and sculpture. Subsequently he came to the 

 conclusion, however, that it was different (an opinion also shared by Jeffreys), and 

 called it T. coniiedens (1st Suppl., p. 30). There is a specimen of this shell in the 

 Ipswich Museum from the Coralline Crag of Boyton, and another from Foxhall at 

 the same place. 



Bellardi states that T. heptagonum is a small shell, 25 mm. only in length, 

 specially characterised by the depth of the suture and its quadrangular mouth, and 

 that it is very abundant at Asti. During a visit to that place some years ago I 

 obtained several specimens of it, one of which is here figured. I have found also 

 an imperfect and worn example at Oakley, as to the identity of which with the 

 latter there seems little doubt. In all probability this form is derivative in the 

 Crag of that place, possibly from some older Pliocene deposit like that of Lenham 

 where Mr. C. Reid observed it, from which some other of the extraneous fossils of 

 the Red Crag may have been derived. 



The species in question does not appear in Seguenza's list of the Pleistocene 

 mollusca of Sicily. 



The T. heptagonum of Homes seems to differ materially from the Asti shell. 

 The tuberculate character of the spiral costae is well shown in the latter, as it is in 

 Brocchi's original figures. 



Triton Woodii, sp. nov. 



1879 Triton connedens (?), S. V Wood, Mon. Crag Moll., 2nd Suppl., p. 15, tab. i, fig. 14. 



Specific Characters. — Shell short, ovate, thick and strong, turreted, whorls 5, 

 Laving a squarish outline above, the last much the largest, two-thirds the total 

 length ; ornamented by strong spiral ridges which thicken and become serrate on 



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