Vol. 31, pp. 135-136 November 29, 1918 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW MARINE MOLLUSK OF THE GENUS CERITHI- 

 OPSIS FROM FLORIDA.* 



BY PAUL BARTSCH. 



Among a lot of shells transmitted to the U. S. National 

 Museum for determination, by Mr. T. Van Hyning, Director 

 of the Florida State Museum, is a minute species of Cerithiopsis 

 which requires a name, and I take pleasure in designating it: 



Cerithiopsis (Cerithiopsis) vanhyningi, new species. 



Shell very small, very elongate ovate. Nuclear whorls 3%, well 

 rounded, smooth, forming a mucronate white apex. Postnuclear whorls 

 chestnut brown, the early ones a little lighter than the last, darkest on 

 the base, the first marked by two slender spiral cords, of which the first 

 is a little anterior to the summit, and the second decidedly posterior 

 to the suture. Beginning with the second postnuclear whorl, a slender 

 spiral thread makes its appearance between the other two, a little nearer 

 to the posterior than the anterior; in fact, it is so close to the posterior 

 that the nodules on the later turns have a dumb bell shaped aspect. This 

 spiral thread gains rapidly in strength, equaling the posterior cord on 

 the third turn. In addition to the spiral sculpture, the whorls are 

 marked by axial ribs which begin as very slight threads and increase 

 rapidly in size with the growth of the shell. The junctions of the axial 

 ribs and the spiral cords form strong tubercles. Those on the posterior 

 and median cord are well rounded and separated only by a slender 

 impressed line on all the whorls except the last, where they are more 

 distantly spaced. Those of the anterior cord are slightly truncated 

 posteriorly, and slope gently anteriorly. The spaces enclosed between 

 the two ribs and spiral cords are strongly impressed rounded pits. 

 Suture weakly channeled. Periphery of the last whorl marked by a 

 strong spiral cord, which is not crossed by the continuation of the 

 axial ribs. The insertion of the columella is surrounded by a strong 



* Published by permission of the Secretary of the Smithsonian Institution. 

 35— Proc. Biol. Soc. Wash.. Vol. 31. 1918. (135) 



