VOL. 



£"•] PROCEEDINGS OF THE NATIONAL MUSEUM. 37 



and two lateral pointed projections, which extend forward to the line of 

 the base of the central ridge, and are defined, laterally, by sharp, nar- 

 row depressions. This; form indicates that two lamella 1 or plates ex- 

 tended out from the beak on each side of a narrow central depression 

 and then curved outward towards the margin, somewhat as in Pentame- 

 rus. In one cast two slight ridges extend from the base of the lateral 

 projections a short distance anteriorly. In the interior of the dorsal 

 valve a transverse depression, just in front of the beak, corresponds to 

 a transverse ridge on the interior of the valve. 



Owing to the imperfect casts of the interior the generic reference to 

 Camerella is tentative. 



In company with Prof. William B. D wight I found this species asso- 

 ciated with heads and fragments of a trilobite that is referred to Oleneh 

 lus asaphoides. 



Formation and locality. — Lower Cambrian. In the quartzitic 

 sandstones of Stissing Mountain, near Stissiugville, Dutchess County, 

 New York. 



Nat. Mus. Cat. Invt. Foss., No. . 



Coleoloides gen. uov. 



Shell slender, elongate, cylindrical, straight or slightly curved, ap- 

 parently thin. 



Surface marked by very fine, slightly oblique, longitudinal stria? in 

 the only species known. 



In form this shell is like that of Hyolithellus micans, but the surface 



markings are unlike those of either Hyolithellus, Billings, or Goleolm, 



Hall. 



Coleoloides typicalis sp. nov. 



Straight, slender, elongate, cylindrical shells that taper so gradually 

 that the diminution in size is only apparent in long pieces of the tube 

 and then observable only by the closest examination. Shell apparently 

 very thin. 



Surface marked by very fine, slightly oblique, longitudinal stria? that 

 are a little irregular in their course, as shown by a strong magnifier. 

 The stria> make one revolution around the tube in a length of sixteen 

 diameters of the tube. 



The longest specimen found has a length of 23 inm and is about one- 

 half a millimeter in diameter. It is broken off at each extremity. 



I do not know of any related species. 



Formation and locality.— Same as Hyolithes terranoricus. 



Nat. Mus. Cat. Invt. Foss., No. 1832G. 



Hyolithes terranovicus sp. nov. 



Form an elongate subtriangular pyramid, gradually and regularly 

 tapering to an acute extremity. The angle of tapering of the dorsal 

 side is very nearly 15°. Transverse section subtriangular or semi- 



