MOLLUSCA. 829 



tral margins, the venter acutely angular ; aperture narrowly sag- 

 gitate in outline. Sutures complex, somewhat crowded ; the ven- 

 tral lobe broad with a minute siphonal saddle, on either side of 

 which is a minute, bifid lobe; at the lateral extremities of the 

 ventral lobe is a pair o>f trifid, palmately spreading divisions; 

 lateral lobes n or 12 in number, the first three much the 

 largest, deeply divided in palmately spreading branches ; beyond 

 the third lateral lobe the lobes rapidly decrease in size, retaining 

 the same style of division but becoming less complicated; lateral 

 saddles rounded or with rounded divisions, the first six or seven 

 bifid, each of the main divisions of the larger ones also bifid ex- 

 cept the first, in which the outer division remains simple while 

 the inner one is bifid. 



Remarks. This species has been identified from mere frag- 

 ments by Whitfield as S. lenticulans Owen, and in some respects 

 it approaches very close to that species, especially to the variety 

 splendent of Hyatt. 1 The suture of a large New Jersey example 

 is fully as complex as, and in many respects more closely re- 

 sembles that of the type of this variety, than it does any of the 

 illustrations of S. lobatus. The smaller saddles, however, of the 

 New Jersey specimens are much more depressed than those shown 

 in the illustrations of $*. lenticidans var. splendens, agreeing in 

 this respect with the figures of >5\ lobatus. In New Jersey the 

 species seems to be characteristic of the Tinton beds as it has 

 not been observed elsewhere, and at least fragments of it have 

 been found wherever fossils have been at all extensively collected 

 from those beds. 



Formation and locality. Tinton beds, Tinton Falls (no), 

 Beers Hill cut (129), near Freehold (132). 



Geographic distribution. New Jersey, Alabama, Mississippi. 



Monog. U. S. G. S., vol. 44, p. 75, pi. 8, figs. 3-7. 



