ORDER ICHTHYOPTERYGIA. 1 1 25 



to have contained parallel bands of muscles set obliquely to the axis of 

 the paddle. In the Latipinnate group (fig. 1 02 7 bis) the posterior flap 

 of integument was narrow in proportion to the bony framework of the 

 paddle, and it was produced inferiorly into a long point below the distal 

 bones. In the Longipinnate group, however, the integuments were much 

 wider in proportion to the bones, and they terminated inferiorly in a 

 blunt extremity, which only reached a short distance below the distal 

 bones. 



1 The larger forms attained a length of from thirty to forty feet ; and it 

 is thought probable that the extremity of the tail was provided with a 

 membranous fin. All the species were carnivorous ; and, as we learn 



Fig. \oi-]bis. — Part of the left pectoral limb of Ichthyosaurus intermedins, viewed from 

 the ventral aspect, and showing the contour of the integument. One-half natural size, hu, Hu- 

 merus; r, Radius; u, Ulna; r 1 , Radiale ; £, Intermedium; it, Ulnare ; c, c' , Centralia. From 

 the Lower Lias of Barrow-on-Soar. 



from the so-called coprolites, their food consisted to a considerable ex- 

 tent of Ganoid Fishes. These coprolites further tell us that the intestine 

 was provided with a spiral valve, as in the Selachian fishes. Perhaps, 

 however, the most remarkable circumstance connected with their internal 

 economy is the not unfrequent occurrence of entire skeletons of small 

 individuals within the thoracic and abdominal cavity of larger ones ; 

 these small specimens being invariably uninjured, and belonging to the 

 same species as the one in which they are contained. This leads Pro- 

 fessor Seeley to conclude that some species or individuals were vivi- 

 parous, and that the young were probably produced of different relative 

 Dulk in different species. There is also evidence to show that in some 

 cases many young were produced at a birth ; the number being perhaps 

 a specific character. It cannot, however, be taken as proved that all 

 Ichthyosaurs were viviparous, since in such other Sauropsida and Ich- 

 thyopsida in which the same mode of development occurs, it is not dis- 

 tinctive of any entire group ; and it is noteworthy that the three specimens 



