No. 7.] WHITEAVES — JURASSIC FOSSILS. 407 



Bpecies, but differ from all those we have seen from rocks of that 

 age in the North West. It is only provisionally we place them 

 along with the Jurassic forms." The finding of P. veternus, in 

 place, associated with fossils that are almost undoubtedly Jurassic, 

 make its age tolerably certain, and strikiugly confirm Mr. Meek's 

 conclusions. Mr. Moore has described another species of Plan- 

 orbis, (P. Mendipensis), from the Charter House Liassic lead 

 mine in the Mendip Hills of Somerset, in rocks of a very similar 

 geological horizon. 



21. Stephanoceras Humphrey sianum, Sowerby, Sp. Sigutlat 

 Lake, one specimen, the only tolerably perfect ammonite in the 

 collection. Prof. A. Hyatt, to whom all the ammonites were 

 Bent for examination, says of this fossil, — "If found in Europe 

 it would be unhesitatingly referred to this polymorphic species 

 and identified with the typical forms." 



22. Stephanoceras Braikenridgii (?) — Sowerby, Sp. Iltas- 

 youco River, two small fragments. " These are very interesting 

 fragments, with all the marks of the mature forms of Steph. 

 Braikenridgii, but ought to be queried because the young char- 

 acteristics are not visible." — Hyatt. 



23. Stephanoceras (?) Seven fragments of a small Steph- 

 anoceras, from the Iltasyouco River, which Prof. Hyatt has 

 compared with European specimens, and pronounces the former 

 to be closely allied to S. Gervillei (Ammonites Gervillei, Sower- 

 by) and S. Platystomum, Reinecke, (sp.) but adds that the 

 young look rather like the early state of S. macrocephalum or 

 S. Herveyi. The penultimate whorl is rather finely ribbed, and 

 the outer surface of the body chamber is quite smooth, at least 

 in the cast ; the umbilicus is not distinctly shown, but it must 

 have been exceedingly small. The shape of the lip is indicated 

 to a certain extent by an obliquely transverse, slightly flexuous, 

 incised groove, which curves forward from the umbilicus, and is 

 produced into a bluntly pointed, beak-like process in passing over 

 the periphery. 



24. Perisphinctes anceps ? Reinecke, Sp. Iltasyouco River, 

 a solitary fragment, which, according to Prof. Hyatt, " has the 

 peculiar abdominal ribs and knob-like spines of P. anceps. The 

 abdomen may have been channelled, and, if so, the above identi- 

 fication could be given without the query." 



25. Belemnites f Seven or eight imperfect specimens of a 



Belemnite with an exceedingly slender parallel-sided guard. 



