l62 NEW YORK STATE AIUSEUM 



Productus dawsoni nov. 

 Specimen nearly subquadrate in outline, widest somewhat in front 

 of the middle. The hinge is slightly shorter than the greatest width 

 of the shell, the lateral margins are concave posteriorly and very 

 gently rounded into the evenly curved anterior margin. The shell 

 is quite depressed for a Productus and the beak barely projects 

 beyond the hinge, not recurving around it. The ears are nearly flat, 

 triangular, carrying many fine spines. The remain- 

 ing characters are common to the rest of the sur- 

 face. The surface of the pedicle vahe is orna- 

 mented with very fine striae which are sharply 

 rounded and narrower than the valleys separating 

 Productus daw- thcni, somcwliat inclined to be wavy, increasing by 



son! no\^. Pedicle . , . ^^, . . , . . , 



valve. miplantation. i he spmes of this form seem to be 



Cape le Trou, Grind- ^ , ' i i -n • i 



stone I. confined to the ears, or nearly so. Posteriorly, 



there are very slight concentric wrinkles. 



Dimensions. Length and width of shell 20 mm, length of hinge 

 15 mm. The specimen figured has a convexity of 4 mm, though it 

 may be very slightly flattened. Fifteen or more striae in 5 mm. 



Remarks. This species is very similar to specimens labeled 

 Productus c o r a var. d a w' 5 o n i Hartt, from the Carbonic 

 limestone of Xova Scotia. It is also very closely 

 related to the form figured by De Koninck from the 

 limestone of A^ise, Belgium, under the term P. 

 s t r i a t u s . 



Productus dawsoni acadicus nov. 



This variety resembles P. d a w s o n i in many 

 of its characters but is much more convex, rela- ^ son^var^ac^a^du 

 tively broader and perhaps has a somewhat more capeie^ivou, orind- 

 protruding beak. ^^°"^ ^• 



Dimensions. Length, 19.5 mm; width, 21.5 mm; length of hinge, 

 17.5 mm; convexity, 7 mm, and slightly flattened. 



Productus arseneaui nov. 



Cast of small size, subquadrate, wn'der than long. Ears small, con- 

 vex, with concentric wrinkles. Hinge-length and transverse 

 diameter of the shell about equal. Lateral margins arcuate; anterior 

 border broadly sinuate, the sinus occupying half its length. The 

 sinus is present over half the length of the pedicle valve. On the 

 surface are about 66 radiating striae, 11 or 12 in 5 mm. They 

 increase in number by implantation and bifurcation, spines sometimes 



