MOLLUSCA. 695 



Description. — Shell acutely angular, the angle of divergence 

 of the sides being about 20°. Suture not strongly impressed, 

 situated in an angular, rounded furrow ; surface of the volutions 

 depressed convex, nearly flat in the central portion and curving 

 more abruptly to the sutures above and below. Surface marked 

 by three major revolving, costse which are flattened on top ; in 

 addition to the major costse there are lower, angular, revolving 

 ribs situated as follows, one between the lower suture and the 

 first major costa, one between the first and second costse, two 

 between the second and third costas, and two between the third 

 major costa and the upper suture. In the casts the sutures are 

 rather close, especially between the lower and larger volutions; 

 the lower volutions are more or less quadrangular in cross-section, 

 the upper ones being rounder, due undoubtedly toi the internal 

 thickening of the shell with age. 



Remarks. — ^The type of this species is the only one observed 

 which preserves any portion of the shell. From its lithologic 

 characters it is apparently from the Navesink marl. The casts 

 from this formation which are referred to the same species are 

 somewhat common and can always be distinguished from the 

 casts of the associated T. vertehroides by the quadrangular cross- 

 section of their larger volutions. The example which Whitfield 

 has illustrated as T. pumila ? from the Manasquan marl is cer- 

 tainly incorrectly identified; the specimen is preserved in the 

 collection of the Philadelphia Academy of Science and, judging 

 from its lithologic characters it came originally from the Nave- 

 sink marl, and it seems to be only a somewhat abnormal ex- 

 ample of T. encrinoides. 



Pormation and locality^. — Navesink marl, Atlantic Highlands 

 (108), Middletown (113^), near Crawfords Corner (126'^), 

 near Holmdel (128^, 127), near Freehold (133), near Wain- 

 ford (148^), Crosswicks Creek (149, 19S), near Jacobstown 

 (150), Mullica Hill (1692). 



Geographic distribution. — New Jersey, Alabama. 



Turritella quadrilira Johnson. 

 Plate LXXVIIL, Fig. 7. 



1898. Turritella quadrilira Johns., Ann. Rep. Geol. Surv. N. J. 

 for 1897, p. 264. 



