G. C. Crick — On Ammonites Ramsayanus. 251 



here, as they have ah-eady been described, but I think it desirable to 

 mention three quartz pebbles which I obtained from one of the 

 workmen. They were all in pieces of chalk, and one is encrusted 

 with a species of Bryozoa. From the finder's description I gathered 

 that they had either come from the highest of the Turonian beds or 

 from the oldest of the Senouian. 



Annexed is a list of the organic remains which I have collected 

 from the above- described sections. The nomenclature of the 

 Selachians is that employed by Dr. A. S. Woodward in his " Notes 

 on the Shark's Teeth from British Cretaceous Formations." ^ With 

 regard to the teeth termed ' Oxyrhina angiistidens/ they are of two 

 kinds — those in which the back portion is smooth and those in 

 which it is striated. I venture to think that these should be referred 

 respectively to Scaphanorhynchis subidatiis and S. rhaphiodon. Like 

 the Selachians, Prolosphyrcena ferox is represented by teeth only, 

 while Cimolicliihys Levesiensis is indicated by a single example of its 

 peculiarly barbed pterygoid teeth. 



IV. — Note on a Chalk Ammonite, probably referable to 



Ammonites Ramsayaiyus, Sharpe. 



By G. C. Crick, F.G.S., of the British Museum (Natural History). 



IN 1856 Sharpe - founded the species Ammonites Ramsayanus upon 

 a single deformed specimen (in the collection of J. Wiest, Esq.) 

 that was obtained from the "Chalk with silicious grains, at Chard- 

 stock, Somersetshire." 



His description is as follows : — 



" A testa discoidea, costata, tuberculata ; anfractibus paucis, sub- 

 compressis : costis continuis, bi-tuberculatis, ad dorsum bifurcatibus : 

 dorso lato, rotundato, costato, utrinque tuberculato : umbilico parvo : 

 apertura oblonga. 



" Shell discoidal, with few, slightly flattened whorls, and a broad 

 rounded back : the whorls are ornamented on the sides by twenty 

 ribs, each of which rise from a small tubercle at the edge of the 

 umbilicus, and has another larger tubercle near the back ; at the 

 latter tubercle each rib divides into two smaller ribs, which continue 

 across the back, and unite again at the corresponding tubercle on the 

 other side of the back : umbilicus small, allowing nearly half of 

 the inner whorls to be seen : aperture oblong : the septa have not 

 been seen." 



Eespecting the type-specimen Sharpe wrote : — " The only specimen 

 which has been seen of this species is deformed, owing, without 

 doubt, to an accident met with when very young. In consequence 

 of this malformation, the two sides have very little resemblance to 

 each other ; and the specific character given above may prove in- 

 correct when more perfect specimens are met with." 



Mr. Jukes-Browne has recently called my attention to an Ammonite^ 



* Proc. Geol. Assoc, vol. xiii (1894). 



2 D. Sharpe: Foss. Moll. Chalk (Mon. Pal. Soc), pt. ill, 1856, p. 51, pi. xxiii, 

 ff. 4a-c. 



^ For the loan of this fossil my best thanks are due to the Rev. H. H. Winwood, 

 M.A., F.G.S. 



