214 A. Smith Woodward — Greensand Ganoid Fishes. 



the affinities of Protosphyrcena,^ and is specially remarkable on 

 account of the shortness of the snout. The type specimen exhibits 

 apparently the greater part of the ethmoidal region, and wants 

 only the extremity of the snout. On the obscured inferior aspect 

 there are traces of the large, laterally-compressed vomerine teeth 

 (Fig. 9a, t,) and there appears to be no flattened area in advance 

 of them. The transverse section is shown to be triangular as 

 described, and on the upper surface there seem to be some feeble 

 indications of coarse longitudinal rugje partly subdivided into 

 tubercles. A second, more abraded specimen (Brit. Mus. P. 7252) 

 has a slightly larger and longer snout with a triangular flattened 

 area immediately in front of the vomerine teeth ; but the differences 

 it presents are not greater than such as may be reasonably explained 

 by individual variation. 



The ganoid fish fauna of the Cambridge Greensand is thus almost 

 as i;nique as its reptilian famia. Nearly every fragment which 

 admits of satisfactory comparison, differs specificall}^ from allied 

 fossils occurring elsewhere ; and the number of forms represented 

 is also remarkable. 



EXPLANATION OF PLATE VIII. 



Fig. 1. Athrodon Jessoni, sp. nov. ; right splenial, from the oral and sjinphysial 



(Iff) aspects. [British Museum, No. P. 7238.] 

 Fig. 2. Cmlodus cantabrigiensis, sp. nov. ; right splenial, from the oral and hinder 



(2ff) aspects. [British Museum, No. P. 7236.] 

 Fig. 3. Anomoeodtis confej'izis, sp. nov. ; right splenial, oral aspect. [Collection of 



James Cai-ter, Esq., F.G.S.] 

 Fig. 4. Anomoeodus Carteri, sp. nov. ; right splenial, oral aspect. [Collection of 



James Carter, Esq., F.G.S.] 

 Fig. 5. Ditto? ; anterior end of left splenial, oral aspect, partly obscured by matrix. 



[Eeed Collection, York Museum ] 

 Fig. 6. lophiostomus affinis, sp. nov. ; hinder portion of cranial roof from the 



upper and right lateral (6ff) aspects ; o. overlapped occipital border ; 



p. jn'ominence above orbit. [British Museum, No. P. 7233.] 

 Fig. 7. Proto^jhyrcena ornata, sp. nov. ; imperfect rostrum, left lateral aspect. 



[Woodwardian Museum, Cambridge.] 

 Fig. 8. Protosphyrcena depressa, sp. nov. ; rostrum, upper aspect, and transverse 



section (8ff). [^Ibid.'] 

 Fig. 9. Protosphyrcena brevirostris, sp. nov. ; imperfect rostrum from the upper 



and left lateral (9«) aspects, t. vomerine tooth. [British Museum, 



No. P. 7253.] 



All the specimens were obtained from the Cambridge Greensand, and the figures 

 are of the natural size. 



attaining a length' of at least 0'19 m., with a transverse diameter of 0-02 m. at its 

 base where the vomerine teeth are implanted ; laterally compressed in its proximal 

 half, the transverse section here being an oval with vertical long axis (Fig. 2b) ; 

 circular in transverse section in its distal portion (Fig. 2c) ; the top of the base 

 gradually becoming flattened as it passes into the cranial roof. External ornament 

 as in P. ferox. 



^ A. S. Woodward, " On the Affinities of the Cretaceous Fish Protosphyrcena,^'' 

 Ann. Mag. Nat. Hist. [6] vol. xiii (1894), p. 510, footnote. 



