46 PALEONTOLOGY OF NEW JEESEY. 



Genus Perissolax Gabb. 

 Synopsis of the MoUusca of the Cretaceous formations, by W. M. Gabb, 1861, p. 66. 

 The geuus Perissolax was founded upon a group of sliells, found in tlie 

 Cretaceous formations, which are characterized by a low spire, rather large, 

 globose or pyriform body volution, and a rather long anterior beak and 

 canal, which is straight or but very little curved, and a columella without 

 plaits or folds. Mr. Gabb cites as types P. (Fnsus) longirostris D'Orb., 

 from Chili, South America, and P. {Fusus) trivolvus Gabb, from the New 

 Jersey Middle Marl Beds. From Mr. Gabb's remarks and the classification 

 of his species in his various papers where it is mentioned, he appears to 

 have considered it as strongly related to Fusus, although in his original 

 description^ of the genus he says: "They have 4iearly the form of the genus 

 Tiulicla or Haustelkim," the latter of which is usually classed with or consid- 

 ered as a synonym of Murex. Mr. Tryon, in his Structural and Systematic 

 Conchology, classes Perissolax under the Bucciiiidce, while Dr. Stoliczka,^ 

 although quite doubtful of its relations, would appear to indicate it as belong- 

 ing to the Muricidce near or among the Fulgurince. After studying the 

 species herein described, in connection with others from other parts of the 

 country, I am inclined to consider them as having their nearest affinities with 

 Haustellwn in the Muricidce, and have so arranged them. The Fiisus longi- 

 rostris, D'Orb., I only know from figures, but the Fusus trivolvis Gabb, the 

 American type, is figured and described in this volume, the type specimen 

 having been used for this purpose. It will be readily seen on comparison 

 that it has more resemblance to HansfeUum than to the typical forms of 

 the genus Fusus, and differs principally in the higher spire and want of 

 periodic varices. Some of the species have, however, nodes or short spines 

 at stated distances on the periphery. The full characters of the beak and 

 canal have not been seen in any of the New Jersey specimens, all the species 

 having been described from casts on which these parts are wanting to a 

 greater or less extent. There can be but little doubt as to its relations, 

 however, with that group of the Muricidce, and none I think as to its valid- 

 ity, even should it prove to be identical with Conrad's genus Pyropsis, to 

 which it is very closely related, as it has precedence in point of time. 



' Synopsis of the MoUasoa of the Cretaceous formations, 1861, p. 66. 

 "Ind. Geol. Surv., Pal. Indica, Cret. Fauna South Ind., vol. 2, p. 113. 



