112 REPORT— 1839. 



The fore-paddles have the same disproportionate size when 

 compared with the hinder ones as in the Idt. commwiis ; but 

 they are not quite so broad in proportion to their length. 



I have found seven series of digital bones in the more perfect 

 specimens of the fore paddle. The first or radial digit divides 

 after the fifth phalanx, and a supernumerary row of small bones 

 is situated at the ulnar edge of cue paddle. The distal ossicles 

 present a similar transversely oblong hexagonal or pentagonal 

 or rounded form as in the Icli. communis. 1 have seen in young 

 specimens of both species a small perforation or pit in the 

 centre of the phalangeal bones ; this marks the situation of the 

 entry of the blood-vessels. It is not, as Mr. Hawkins seems to 

 suppose, a specific peculiarity of the intermedius. 



This species appears to be the most common, if not the most 

 generally distributed of the Ichthyosauri. 



It is smaller than the Ich. communis. I have not seen any 

 specimen exceeding seven feet in length. 



Localities. — The remains of the Ichthyosaurus intermedius 

 are common in the lias of Street ; they have been found at 

 Lyme Regis and Charmouth ; in the lias near Weston, Bath, and 

 Bristol ; at Keynsham ; in the lias at Charlton, about two miles 

 from Cheltenham ; and at Bedminster ; in the limestone lias at 

 Stratford, Warwickshire; likewise at Barrow- on-Soar, Leices- 

 tershire, but here less common than the Ich. communis. The 

 Ich. intertnedius also occurs in the lias near Whitby and Scar- 

 borough ; in the lias of different parts of Yorkshire ; at Bolsover 

 in Nottinghamshire ; at Whitton in Lincolnshire ; at Walgrave 

 in Northamptonshire. In almost every museum, indeed, I have 

 found remains more or less perfect of this species. 



The head of the Ichthyosaurus from the lias-field of Boll, 

 figured by Prof. Jager, does not belong, as he conjectures, to the 

 Ich. intermedius, but to the species I shall presently have to 

 describe under the name of Ich. acutirostris, and which is more 

 nearly allied to Ich. tenuirostris* . 



Ichthyosaurus platyodon, Conybeare. 



giganteus, Leach. 



Cheiroligostinus, Hawkins. 



The species which I am now about to describe is that which 

 Mr. Hawkins has figured in his memoirs on Ichthyosauri 

 (PI. Til.) under the name of Cheiroligostinus, and of which 

 Dr. Leach had previously figured portions of the jaws and teeth 

 under the name of Ich. giganteus. The skull and scapula 



* The small specimen of Ichthyosaurus figured by Sir Everard Home under 

 the name of ' Proteosaurus' belongs to the pi-esent species and not to Ich. te- 

 nuirostris as Ciivier supposed. 



