NO. 2 PYRAMIDELLID MOLLUSKS — BARTSCH 5 1 



St. Petersburg, Fla. It is a young specimen and has 8.4 whorls and 

 measures: Length 3.5 mm. (this is a false length measurement of 

 the shell since the basal part of the outer lip and columella are broken 

 away) ; diameter i mm. 



An additional young specimen from the same source is in the 

 collection of the A.N.S.P. 



The shouldered whorls will readily distinguish this species from 

 the rest of Pyrgiscus. 



PYRGISCUS TELAMONI, new species 

 Plate 9, figures 3a, b 



Shell large, turrited, cream-yellow. The nucleus is small and con- 

 sists of about 2 whorls that form a depressed helicoid spire whose 

 axis is at right angles to that of the postnuclear spire, in the first 

 whorl of which the nucleus is about one-fourth immersed. The post- 

 nuclear whorls are slightly rounded and crossed by strong, slightly 

 retractively slanting axial ribs, of which 12 are present upon the first 

 and second, 14 upon the third, 16 upon the fourth, 18 upon the fifth, 

 20 upon the sixth, 24 upon the seventh, and 28 upon the last whorl. 

 These ribs are of the same strength from the summit to the periphery. 

 The intercostal spaces are about as wide as the ribs and are crossed by 

 eight spiral pits that differ greatly in size and spacing and are best 

 visualized by our sketch, plate 9, figure 3b. Suture moderately im- 

 pressed, rendered wavy by the summit of the axial ribs. Base hemi- 

 spherical, marked by the continuation of the axial ribs, which be- 

 come gradually weaker after passing the periphery and vanish before 

 reaching the middle of the base. The base also has nine weak spiral 

 cords, which gradually become finer from the periphery toward the 

 tip of the base. Aperture elongate, obliquely oval ; the columella has 

 a strong oblique fold a little below its insertion; the outer lip is 

 fractured. 



The type, U.S.N.M. No. 561658, comes from the Pliocene deposits 

 of North St. Petersburg, Fla. It has 8.5 postnuclear whorls and 

 measures: Length 5.5 mm., diameter i.i mm. The type is a not quite 

 adult specimen. U.S.N.M. No. 561659 is a fragment of a more 

 mature specimen ; this has 4.4 whorls and measures : Length 4 mm., 

 diameter 1.2 mm. 



The nine spiral threads of the base will readily distinguish this 

 species from its near relatives. 



