74 BRITISH FOSSIL REPTILES. 



anterior ones, are well developed, and the vertebrae of the trunk and basal moiety of the tail 

 are strongly interlocked, though admitting some inflection. The ribs increase in length 

 to the twenty-fifth pair ; at the thirtieth pair they begin to shorten gradually, and, after 

 the fortieth pair, more suddenly, becoming nearly straight at the forty-fourth pair. 

 Thence they are continued like long transverse processes articulated by a simple head to 

 the single di-parapophysis, as far as the hundredth vertebra. 



The scapula (Tab. XXVII, fig. 3, 5i) has a relatively broader humeral end than usual. 

 It is preserved with the corresponding clavicle (ib., as) in a portion of a huge skeleton of 

 the present species in the British Museum. 



The coracoid has a relatively larger or longer scapulo-humeral surface than in Ich. 

 intermedins, and has a narrower and deeper anterior notch or emargination than in Ich. 

 communis; the ento-sternal margin is rather thicker than usual. I have noted a 

 specimen of this bone from Lyme Regis, of which the long diameter was 8 inches 4 

 lines, the short diameter 6 inches.^ 



The humerus is notable for its breadth, especially distally, compared with its length- 

 The proximal rounded end, or ' head,' is tuberculate at its circumference, indicative of 

 powerful ligamentous attachments to the scapulo-coracoid joint. The fore margin is 

 more concave than usual. This latter character is still more marked in the radius, which, 

 with the ulna, presents the generic shortness and flatness, with a slight excess of breadth, 

 as compared with most other species. The anterior emargination is present also in the 

 radio-carpal bone (Tab. XXVII, fig. 1, 54), and in the corresponding one in the following 

 series. The next ossicle presents the common pentagonal form. Not more than three 

 series of digital bones are preserved in the subject of figure 1, Tab. XXVII. A few 

 supplemental ossicles are preserved at the radial border beyond the middle of the fin- 

 framework. I have not found evidence of a greater number of pectoral digits in any 

 remains of the present species. It seems to have been characterised by long and 

 narrow, but powerful fore paddles. 



In the pelvic bones the ilium (Tab. XXVII, fig. 1, C2) presents a straight, flattened, 

 slender form. The ischium (ib., G3) is remarkable for its breadth, especially at its 

 medial end. The pubis (ib., 04) is less expanded there ; its anterior border is straight. 



The femur (ib., 60) is longer in proportion to its breadth than the humerus ; its 

 proximal end shows a large depression, probably for the insertion of a stout ligament. 

 The tibia (ib., 66) presents an anterior emargination, as in the radius (54) ; the same 

 character is repeated in the two succeeding ossicles at the same margin of the fin- 

 framework. Here, also, but three digital series are preserved, with a few small 

 supplemental ossicles along the fibular border of the fin. 



The disposition of the distal ossicles in both pairs indicates that the ligamentous or 

 fibro-cartilaginous uniting medium of their framework may have been more abundant 

 than usual, allowing greater flexibility of the terminal part of the long and narrow 



1 ' Report,' ut supra, 1839, p. 114. 



