OPHIDIA. 313 



The earliest evidence of an ophidian reptile has been ob- 

 tained from the eocene clay at Sheppy ; it consists of vertebra? 

 indicating a serpent of 12 feet in length, the Pcdccoplus toliapi- 

 cus (fig. 103, 5, half nat. size). Still larger, more nnmerons, and 

 better preserved vertebrae have been obtained from the eocene 

 beds at Brackleshani, on which the Palceophis typhecus and P. 

 porcatus have been founded : * these remains indicate a boa- 

 constrictor-like snake, of about 20 feet in length. The fossil 

 vertebrae shew the deep and well-defined anterior cup, a, and 

 posterior ball b ; the cliapophysis d differs from that of the boa- 

 constrictor in being more prominent and more uniformly 

 convex ; the hypapophysis h is short, as in the constrictors ; zs 

 is the anterior, and z the posterior zygapophysis ; the posterior 

 border of the neurapophysis is remarkable for the angular 

 process n. The accessory articular surfaces at the fore-part of 

 the neural arch are supported, as in recent ophidian vertebrae, 

 upon the process z, called the zygosphene. Ophidian vertebrae 

 of much smaller size, from the newer eocene at Hordwell, 

 support the species called Paleryx rhombifer and P. depressus.l 

 Fossil vertebrae from a tertiary formation near Salonica have 

 been referred to a serpent, probably poisonous, under the name 

 of Laophis.\ One of these vertebrae (fig. 103, 5) shews the 

 accessory process d below zs, and the long hypapophysis, h. 

 Poison-fangs of apparently a viper, and vertebrae of a Coluber 

 three times the size of any existing European species, have 

 been discovered in the miocene deposits at Sansans, south of 

 France. Three fossil Ophidians from the CEningen slate have 

 been referred to Coluber arenatus, C. Kargii, and C. Oivenii. 



A few bones of serpents have been found in superficial sta- 

 lagmite and in clefts of caves, which, perhaps, are within the 

 period of human history. But what is of chief interest to us is 

 the fact of the existence of ophidian reptiles of the constricting, 



* Op. cit., pp. 139-149, pis. 2 and 3. t Op. cit., p. 149. pi. 2, figs. 29-32. 



X Quarterly Journal of the Geological Society, vol. xiii., p. 196, pi. iv. 



