234 Beijrlclda Chamhersi — Tentaculites Eichmondensis. 



Beyrichia Chamhersi — (S. A. Miller). 



Fig. 27 — Beiiriehia Chambersi, magnified about twelve diameters. 



Shell small, subreniform, dorsal margin straight, nearly as long as 

 the entire length of the shell, basal margin subelhptical ; anterior end 

 wider than the posterior. The body of the valve is crossed by two 

 broad, deep sulci, one of which is situated immediately behind the eye 

 tubercle in the anterior third, the other in the middle third of the 

 shell. The projecting basal margin is marked with a depression 

 throughout its length, and bordered with a carinated edge. 



The eye tubercle is about as long as the breadth of the shell, and 

 rises like a half cone from the extreme anterior end, with the flattened 

 face in the rear marked by fine oblique lines, very much resembling in 

 appearance, when magnified, the teeth of a comb. 



Greatest length of the shell about y^-th inch ; breadth, one third less. 



This species is readily distinguished from all others by the remarka- 

 ble eye tubercle. In other respects it most nearly resembles B. oculi- 

 fer (Hall), though not exactly correspondmg with it. 



I first found it in the excavation for Columbia avenue, in Cincinnati, 

 about 150 feet ' above low water-mark ; subsequently I found it at 

 Richmond, Indiana, in the upper part of the Cincinnati Group, thus 

 indicating that its range is co-extensive with the exposure of the blue 

 limestone. I found, however, only one slab at Richmond and two at 

 Columbia avenue bearing the fossil, and do not know of any others 

 having been found, but, considering its great range, we must expect to 

 find it in some locality in great abundance, and the only reason this 

 has not thus far been accomplished is most likely owing to the extreme 

 minuteness of the fossil. 



The specific name is given in honor of our most eminent naturalist 

 and learned entomologist, V. T. Chambers, Esq., of Covington, Ky. 



Tentaculites liichnondensis — (ii. A. Miller). 



Tube free or detached, straight, conical, gradually tajoering from 

 the aperture to an obtuse point. Surface marked by strong encircling 

 anuulations or constrictions, which are crossed by very fine, regular, 

 longitudinal strice. 



