2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



Most of the difficulties have been due to the fact that authors have 

 been loath to increase the number of genera in the family, which has 

 already 326 generic names to its credit. Also, most authors have lacked 

 the necessary genotypes to fix definitely the characters of each genus. 



Realizing the confusion that has existed and still exists in the no- 

 menclature of this family, I have been acquiring genotypes of it for 

 the National Museum for some time and can now say that the Museum 

 has specimens of almost all of them, or, where specimens are not 

 available, photographs of them. It is this collection of genotypes that 

 l^rings to light the woeful inadequacy of names, and in reviewing 

 even as limited a fauna as that here in part discussed, it becomes 

 necessary to add many new names. 



In the examination of the turritids I find that the nuclear characters 

 here as elsewhere yield useful elements in the definition of groups, 

 but these are points which may be discussed in detail in the final paper, 

 which will give an account of all the mollusks obtained in the Puerto 

 Rican Deep, not merely the new forms here made known. 



ELDRIDGEA, n. gen. 



Type species. — Eldridgca johnsoui, new species. 



Shell moderately large, ovate (early nuclear whorls unknown). The 

 first of the remaining nuclear whorls apparently smooth. The early 

 post-nuclear whorls strongly axially ribbed. Those succeeding marked 

 by expanded foliations that take the place of ribs. These broadly ex- 

 panded elements are best understood by examining the figures (pi. i, 

 figs. 1-3) ; they suggest the ornamentations of certain Boreotrophons. 

 The outside of the expanded wings, the base, and the columella are 

 marked by more or less equal and equally spaced spiral lirations. The 

 inside of the foliations is smooth. Aperture large. Posterior sinus 

 immediately below the summit ; stromboid notch very shallow ; inner 

 lip appressed to the columella ; parietal wall covered with a thin callus, 

 which forms a nodule at the posterior angle. 



This genus suggests Clavus Montiort = Clazncantha Swainson and 

 Tylofia Melville, in which the ribs are spinose or slightly lamellosely 

 expanded, but the present genus carries this to an extreme point. 



ELDRIDGEA JOHNSONI, n. sp. 



Plate I, figs. 1-3 



Shell moderately large, ovate, horn-colored, with the inside of the 

 alations and the broad basal band white ; interior of aperture porce- 

 laneous with a pinkish tinge. A part of the first turn of the nuclear 



