378 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. IV. 



" more acutely conical than in Ichthyosaurus communis, and 

 the striae less prominent ; but are less slender than in Ich. 

 tenuirostris." There are other characters, alike intermediate 

 between those of the above-named species, but which would 

 be unintelligible to the reader, without figures. " The maxil- 

 lary portion of the skull is relatively shorter, and converges 

 more regularly to the snout, than in Ich. communis ; and the 

 teeth are longer, more slender and numerous. 1 In a skeleton 

 in Mr. Johnson's museum at Bristol, there were =2." The 

 number of vertebrae exceeds 125. The orbit is large, and has 

 16 or 18 sclerotic plates. 2 



This Ichthyosaurus does not exceed seven feet in length ; it 

 is the most common species, and its remains are very gene- 

 rally distributed throughout the Lias of England. 



ICHTHYOSAURUS LONGIPENNIS. Wall-case A. The fossil 

 thus labelled, is from the Lias of Whitby, in Yorkshire. It 

 consists of a cranium with the jaws and teeth, a confused mass 

 of the anterior part of the trunk, a few bones of one fin, and 

 a nearly perfect paddle, the humerus of which is short and 

 very strong. The carpals, metacarpals, and digitals, comprise 

 thirty rows of ossicles ; the fin must therefore have been very 

 long and tapering, if the present bones are the normal number; 

 but it seems probable that the paddle was wider in proportion 

 to its length, and that many ossicles are lost. I am not aware 

 of any published description of this species. 



ICHTHYOSAURUS COMMUNIS S (Conybeare). Wall-cases A and 

 D. Of this species there is a most beautiful specimen with 

 the anterior and posterior paddles, in the lowermost compart- 

 ment of Case A* and another nearly perfect skeleton in the 

 upper division of Case D, 



1 Prof. Owen in "Brit. Assoc. Rep." p. 110, which the scientific 

 inquirer should consult for anatomical details. 



2 This species is named by Mr. Hawkins chiroparamekostinus, (or 

 oblong-boned paddle,) from the oblong form of the phalangeal ossicles ; 

 a character which, however, is not peculiar to this species. See " Memoirs 

 on Ichthyosauri," p. 32. 



3 " Brit. Assoc. Rep." 1839, p. 108. 



4 I cannot resist the insertion of the following racy account of the 

 discovery and exhumation of this exquisite fossil. One Jonas Wish- 

 combe, a fossil dealer, of Charmonth, had perceived the remains of an 

 enormous Ichthyosaurus at low water, but in a situation so unfavourable 



