34 NEW YORK STATE MUSEUM 



eccyliopterus Reinel£ 



Eccyliopterus spiralis sp. nov. 



PL 2, fig. 9, 10 



A specie® of Eiccyliopterus found' in, a pebble of black com- 

 pact limestone from the conglomerate of the Moordener kill 

 and associated with cranidia of Pterygametopus c a 1 1 i - 

 cephalus and with Plectambonites pisum differs 

 from its 'three Trenton congeners in being very loosely coiled. 

 It may therefore be described here as new, though as yet known 

 only by a single somewhat imperfect specimen. 



Whorls strongly evolute, lying nearly in the same plane, ap- 

 parently not more than two in number; enlarging quite rapidly, 

 more in hight than in width. Upper side of shell marked along 

 the outer margin by a carina extending into the collar, charac- 

 teristic of Eccyliopterus; upper side sloping concavely inward, 

 outer side nearly vertical, slightly convex; under side strongly 

 convex. The collar is only partially preserved, its hight and 

 extent therefore unknown. Aperture nearly vertical to the 

 plane of the shell, ovate. Faint close growth lines are notice- 

 able on the under and outer side of the specimen. 



Dimensions. Length 35.2 mm, greatest width of volution 9.4 

 mm, greatest hight 10.8 mm. 



Observations. This species may be easily distinguished from 

 Eccyliopterus (O p h i 1 e t a) ottawensis Billings, 

 from the Canadian Trenton; from E. (O p h i 1 e t a) owenanus 

 Meek and Worthen, from the Trenton of Minnesota, as well 

 as from E. b e 1 o i t e n s i S Ulrich and Scofield, from the Stones 

 river group of Wisconsin and Kentucky, by its evolute and loose 

 instead of contiguous whorls. In this regard as well as in the 

 section of the whorls it is more related to E. (E c c y 1 i o m p h a - 

 1 u s) v o 1 u t a t u s Whitfield, from the Fort Cassin beds, from 

 which it differs in having a straight mouth, and considerably 

 more rapid enlargement of the volutions. (Group 5) 



