284 A. j, JIJKES-BEOWNE ON THE RELATIONS OP 



Such guidance has, in the present instance at any rate, enabled 

 me to add 16 more species to the lists of the Cambridge fauna, and 

 to identify at least 12 others as belonging to different species from 

 those to which they had been previously referred. 



That in these additions and corrections I have not been led astray 

 by theoretical considerations will, I think, be granted when they are 

 confirmed by so high an authority as that of Mr. Etheridge. In the 

 majority of instances he has been able to do this by reference to the 

 Cambridge fossils in the Jermyn- Street collection, which he and 

 Mr. Newton were kind enough to re-examine with me for the pur- 

 pose ; it is only a few rarer species, not represented in the Survey 

 Museum, that stand on my authority alone. 



The lists of Reptilia in the following catalogue are taken from 

 Mr. Seeley's ' Index to the Remains of Reptilia, &c, in the Wood- 

 wardian Museum of Cambridge ; ' the names of new species herein 

 mentioned are stated to be only provisional, and a note on p. xv of 

 the above ' Index ' is thus worded : — " These names are only in- 

 tended for the convenience of students using the Museum, and are 

 not necessarily to take rank as names of described species." In very 

 few cases, so far as I am aware, has Mr. Seeley subsequently raised 

 any of the specimens so named to the rank of species by a detailed 

 description of the same ; in default, however, of any other list of 

 the Cambridge Reptilia, I have judged it best to admit all Mr. Seeley's 

 names into my own catalogue, but have not included them in calcu- 

 lations of the number of species for comparison with other faunas. 

 I have carefully examined the specimens in the Woodwardian Mu- 

 seum in order to separate the dark, rolled, derived bones from those 

 preserved in Chalk-marl only ; this is an easy task with the remains 

 of the Dinosaurs, Ichthyosaurs, and Plesiosaurs, but becomes much 

 more difficult with those of Pterodactylus on account of the different 

 structure of its bones. I will not, therefore, be positive that all 

 those entered under the Gault fauna have been derived therefrom, 

 though bones of Pterodactylus have been found in the Folkestone 

 Gault, and I am sure that many have been derived from that forma- 

 tion. The same is the case with the fish-remains of the Cambridge 

 deposit. 



The following remarks relate to the identification of some species, 

 and to the synonymy of others hitherto regarded as distinct,, 



I have to thank Mr. Etheridge and Mr. Newton, of Jermyn Street, 

 for assistance in this department. 



Pisces. 



Lamna sijbtjlata, Ag. 



Lamna subulata, Pict. & Campiche, Ste.-Croix, i. p. 87, pi. xi. f. 1-8. 



The teeth of this species have been recognized in the Wood- 

 wardian Museum as Lamna, sp. I entertain little doubt of their 

 belonging to the above species, which MM. Pictet and Campiche 

 refer to their subgenus Odontasjpis. The teeth are long and subulate, 



