Dawkins—On Rhinoceros leptorfiinus. 257 



the forest-bed of the Norfolk shore, and like the B. megarJimus, 

 found in the Pliocene of France and Italy; it ranged across the 

 Pyrenees as far as Malaga, and is the only species known to occur in 

 Spain. The fourth, the B. leptorJiinus of Professor Owen, is the 

 equivalent of the the B. Jiemitoechus of Dr. Falconer. In common 

 with the other British rhinoceroses, it possessed a molar series of six 

 only on either side, and was two-horned. It ranged through Eng- 

 land from the Hysena-den of Kirkdale, Yorkshire, in the north, as 

 far south as the plains of Somersetshire, and as far to the west as 

 Pembrokeshire. It is very generally found in association with 

 Elephas antiquus and Hippopotamus major, both of which species lived 

 in Pliocene times. 



Its association in Wookey Hole Hyaena-den with ElepJias primi- 

 genius, and B. ticliorMnus and other characteristic Post-glacial mam- 

 mals, proves that the leptorhine rhinoceros co-existed with the 

 tichorhine species, to which it probably bore the same geographical 

 relation as the elk does to the reindeer in the high northern 

 latitudes. The sum of the evidence proves that it was coeval with 

 the mammoth and tichorhine rhinoceros, and does not characterize 

 the deposits of an earlier epoch than the Pleistocene. It has not as 

 yet been found in Pre-glacial formations. The B. leptorliinus is more 

 closely allied to the bicorn rhinoceros of Sumatra than to any other 

 living species. 



H. — An Epitome of the Evidence that Ptekodactyles ake not 

 Eeptiles, but a new Subclass of Veetebeate Animals allied 

 TO Birds [Saurobnia) . 



By Harky Seeley, F.G.S. 

 [Ann. and Mag. Nat. Hist. May, 1866.] 



AFTER a discussion on the several opinions regarding the zoolo- 

 gical relations of the Pterodactyles, Mr. Seeley explains, from his 

 own researches, the anatomical structure of those so-called " flying 

 reptiles," and sums up in the following words : — " From facts, such 

 as these, it seems to me no hard task to determine whether the Pte- 

 rodactyle has the organization of a reptile or of a bird, I find it in 

 every essential principle to be formed on the avian plan. Yet it 

 diifers more from existing birds than they do among themselves, and 

 therefore cannot be included as an order of Aves ; for the points of 

 structure in which it differs from birds are those in which all exist- 

 ing birds agree. I therefore regard it as forming a group of equal 

 value with Aves (Sauromia), each as a sub-class, forming together a 

 great class of birds. Its distinctive characters are — in having teeth, 

 ia the simple convex or concave articulation of the vertebrse in the 

 separate condition of the tarsal and metatarsal bones, in having three 

 bones in the forearm instead of two, in a peculiar carpal bone, in the 

 sacrum formed of few vertebras, and in the modification of the wing 

 by the enormous development of the phalanges of one finger. The 

 sub-class so characterized fonns a parallel group with the true birds. 

 Whether it may not in some points of organization rise above birds, 

 VOL. in. — NO. XXIV, 17 



