Description of Three JVeiv Species. 



117 



Orthoxotella, n. gen. 



[Ety. — Orthos, straight; notos, back; ellus, diminutive.] 



Shell minute, thin, elongate, more or less elliptical, very inequivalve 

 and inequilateral; hinge line straight behind the beaks; ligament ex- 

 ternal. T}'pe, Orthonotella faberi. It is difficult to determine from 

 the exterior of a single specimen the family affinity of this genus. 

 The absence of a wing, and the straight hinge line back of the beaks, 

 would not allow it to fall within the Pterinidce, while the great ine- 

 quality of the valves and minute size, evidently preclude it from the 

 Orthonotidoe and Mytilidm. 



Orthoxotella faberi, n. sp. 



Plate V., fig. 7, left valve magnified.8~dianieters ; fig. 7«, hinge line magnified 8 diam- 

 eters ; fig. 76, natural size of the shell. 



Shell very small, thin, broadly elongate-elliptical in outline, two and 

 a half times as long as wide; cardinal and basal lines for a short dis- 

 tance posterior to the beak, straight and parallel. Left valve slights- 

 convex toward the posterior end, but more ventricose in the anterior 

 part and on the umbonal region ; beak rather large, obtuse and quite 

 terminal. Surface marked by fine concentric lines. Right valve flat 

 in the posterior half and lower part, but having a slightly convex um- 

 bonal elevation at the anterior end, terminating in an obtuse beak 

 somewhat smaller than that on the left valve. Surface apparently 

 smooth. Interior unknown. 



Collected by C. L. Faber, Esq., in the Hudson River Group, at Cin- 

 cinnati, Ohio, at an elevation of about three hundred and fifty feet 

 above low water mark, in the Ohio River. 



Lyriocrinus sculptus, S. A. Miller. 



B\- mistake this species was erroneously printed Lyriocrinus sculp- 

 tilis s in the July number of this Journal, page 83, and also opposite 

 plate 3. The error was discovered in time to correct it in the author's 

 edition. As sculptilis was a preoccupied specific name, Lyriocrinus 

 sculptus must be used. 



Calymene callicephala, Green. 



Plate V., fig. 8, showing a spiral appendage beneath the fixed cheeks of the cephalic- 

 shield. 



This specimen is from the upper part of the Hudson River Group, 

 near Waynesville, Ohio, and belongs to the collection of I. H. Harris. 

 The fixed cheeks upon each side have been worn away, showing a test 

 below furrowed in the manner of a spiral appendage, as shown in the 

 figure. It is figured for the purpose of calling attention to it, that 

 it mav be better understood. 



if 



