On the Fossil Vertebræ of a Serpent (Laophis crotaloïdes, Ow.) discovered by Capt. Spratt, R.N., in a Tertiary Formation at Salonica*

The characters for distinguishing and determining the fossil remains of Serpents are deemed, I believe, by most palæontologists to be less salient and satisfactory than in those of other reptiles. I have found, however, in the course of comparisons called for by the discovery of Ophidiolites in our own tertiary strata, more differentiating characters in Ophidian vertebræ than the works on comparative anatomy gave promise of; and no palæontologist would find a difficulty in distinguishing the vertebra of an eocene Palœophis (PI. IV. fig. 1), e.g. from that of any known existing Ophidian, provided the neural arch (n, z) were entire. For the nomenclature of the parts and processes of an Ophidian vertebra, and for their chief modifications in existing Serpents, I must refer to my “History of British Fossil Reptiles,” pp. 135–139, Ophidia, plates 2 and 3. It will there be seen that in the genera Python (figs. 5 and 6), Boa, Eryx, Coluber (fig. 7), Deirodon, and Hydrus, the hypapophysis (h) subsides into a ridge, or a short subcompressed tubercle, in the vertebræ situated, behind the anterior third or fourth part of the trunk; but that in Crotalus (fig. 4), Vipera, and Natrix the hypapophysis, h, is continued, with more or less diminution of relative length, from all the vertebræ supporting free ribs.