274 Dr. T. "Wright on Fossil Echinoderms 



Genus Eufatagus, Agassiz, 1847. 



Spatangoid Urchins^ with a cordate or elliptical form, more or 

 less depressed ; the petaloid portions of the antero- and postero- 

 lateral arabulacral areas are wide ; the single area is lodged in 

 a shallow anteal sulcus, and the entire ambulacral star is closely 

 surrounded by a broad well-defined peripetal fasciole, which 

 undulates round its margin ; within this fasciolar space, the in- 

 terambulacral plates carry very large perforated tubercles raised 

 on crenulated bosses, and surrounded by wide smooth areolas, 

 like those in the genus Spatangus. The heart-shaped shield, 

 beneath the anal opening, is likewise surrounded by a well- 

 defined subanal fasciole. The basal portions of the postero- 

 lateral ambulacra form broad, naked bands, between the poste- 

 rior border and the mouth. The other characters resemble those 

 of Spatangus, from which it differs however in possessing a peri- 

 petal fasciole. 



Eupatagus De Koninckii, Wright, n. sp. 



Syn. Spatangus De Koninckii, Wright, Ann. of Nat. Hist. vol. xv. 

 p. 178. 



The test of the original specimen of Eupatagus De Koninckii 

 having had the external layer of its shell and consequently its 

 fascioles denuded, we are now enabled to correct our determi- 

 nation of this species from a specimen in the collection of the 

 British Museum, in which these important parts of the anatomy 

 of the skeleton are well preserved. For the description of this 

 Urchin see our article Spatangus De Koninckii, to which we 

 subjoin the following note : — The peripetal fasciole is rather 

 broad, surrounding with little undulation the ambulacral star, 

 and forming a well-defined boundary between that portion of 

 the upper surface with large perforated tubercles, and that part 

 with very small tubercles; the subanal fasciole heart-shaped, 

 rather broad, and enclosing a shield-like space filled with larger 

 tubercles ; it extends from the prominent point of the base to 

 near the lower part of the anal opening. 



Scalaria Duciei, Wright, n. sp. PI. VII. fig. 4 a, b. 



Diagnosis. — Shell turriculated, imperforate ; spire gently taper- 

 ing ; whorls ten, with transverse prominent plates and longi- 

 tudinal elevations. The transverse plates, nineteen in number 

 on the body- whorl, are formed of numerous thin shelly laminse, 

 closely united where they proceed from the whorl, but out- 

 wardly they expand and form a rather irregular undulated sur- 

 face ; each plate describes three curves ; two of these, the 



