700 E. C. CASE 



Janassa gurleyana Cope. Plate I, Figs. 2a, 2b, 2c. 



Strigilina gurleiana Cope, 1877, Proc. Am. Phil. Soc., p. 191. 



(Pal. Bull., No. 26.) 

 Janassa gurleia?ia Cope, 1881, Am. Nat., p. 163. 

 Janassa gurleiana Woodward, 1889, Cat. Foss. Fishes Brit. 



Mus., Pt. I, p. 39. 



" The tooth is quite small, its length only equaling the width of the known 

 tooth of 6". {Janassa) linguaformis. It is also narrower in proportion to the 

 length. The root and the cutting edge are turned in opposite directions as 

 in the other species. The principal difference between the two is seen in 

 the character of the transverse ridges or crests of the oval face. There are 

 two crests less, or five, with a delicate basal fold, making six, while, count- 

 ing the fold, there are eight in S. [Janassa) linguceformis. The anterior 

 ridge is transverse ; the others slightly convex backwards, and all are equi- 

 distant and uninterrupted, which is not the case in the older species. They 

 are also of different form, being distinct ridges with anterior and posterior 

 faces similar. In S. (Janassa) lingucejormis the anterior face only is vertical, 

 the posterior descending very gradually, the whole forming a series of steps. 



"Length of the ridged face, .oo6o m ; width anteriorly, .0035™; width pos- 

 teriorly, .0020 m ." 



[No. 6501.] 



Pleuracanthus (Orthacanthus) quadriseriatus Cope. Plate I, Figs, 

 3^, lb. 

 Orthacanthus quadriseriatus Cope, 1877, Proc. Am. Phil. Soc, 



p. 192. (Pal. Bull., No. 26.) 

 Pleurae antlius quadriseriatus Woodward, 1889, Cat. Foss. 



Fishes Brit. Mus., Pt. I, p. 9. 



Represented in the collection by imperfect radial spines. Both Newberry 

 and Cope remark that it is very likely that the spines called Orthacanthus 

 may belong to the the same fish as the teeth called Didymodus {JDiplodus), 

 and as the teeth are distinctly referable to the genus Pleuracanthus Ag., it is 

 perhaps best to follow Zittel in regarding all three names as synonyms of 

 Pleuracanthus. The teeth and spines are found in close connection. The 

 species here described differs from the O. gracilis of Newberry in hav- 

 ing the denticles shorter. The description given by Cope is as follows : 

 "The spine is wider than deep, and the series of denticles are widely sepa- 

 rated. The surface between them is gently convex and smooth. The 

 anterior face is strongly convex, and presents at each side two shallow fur- 

 rows. The external groove is divided by a series of thin longitudinal 

 denticles which are smaller than those of the principal row, and which are 



