26 Notes on the Genus Pineria. 



An examination of the lingual teeth of the varions forms of 

 Macroceramus, and of Pineria from the Isle of Pines, is ex- 

 tremely desirable, and also of the soft parts of the latter, in order 

 to settle the question raised by Poey as to the tentacles. In the 

 meanwhile we continue to use the generic name Pineria. 



The following is a description of the jaw and lingual denti- 

 tion of P. Viequensis : 



Jaw so extremely tliin. and delicate that it curls or folds over upon 

 itself along the edges, and at tlie extremities ; pale horn-color, translu- 

 cent ; strongly arched, svibcircular ; of nearly equal height througliout, 

 the ends slightly attenuated and blunt ; entire, but with the appear- 

 ance of being divided perpendicularly into about twenty-eight sepa- 

 rate sections or folds, the outer margin of each defined by a thicken- 

 ing of the substance of the jaw ; the sections curve strongly out- 

 wards, excepting at the upper centre of the jaw, where they are 

 arranged en chevron upon the central line ; either margin serrated by 

 the extreme outer edges of the sections or folds ; generally resembling 

 the jaws of Macroceramus and Cylindrella^ as figured in Ann. Lye. 

 viii. 162. ; ylm. tTour. Conch, iv. 187, v. pi. xi. ; tFourn. de Conch. 

 xviii. 1, pi. iii. and v., Jan. 1870. 



Lingual membrane very long and narrow, composed of numerous 

 rows of teeth arranged obliquely from below upwards en chevron ; 

 teeth arranged in quincunx 2. 1. 2 in each row, with several additional 

 rudimentary marginal teeth ; central teeth small, long, slender, 

 crowded between the first laterals, its apex recurved into a rounded 

 cusp ; first lateral broad, bicu.spid, base of attachment subquadrate, 

 lower cusp very large, broader than the base, subcircular, upper cusp 

 very small, seated on a long, slender neck, which curves gracefully 

 outward and upward beyond the apex of the central tooth; second 

 lateral of the same shape as the first lateral ; marginal teeth five or six, 

 arranged in a crowded row running obliquely upward and outward 

 from near the base of the outer lateral, decreasing rapidly in length 



* Crosse and Fischer, in their description of the jaw of Cylindrdla, remark 

 that it is furnished with very fine ribs, which are shown under the microscope 

 to be nothing less than a complete folding of the substance of the jaw. 



