376 ZOOLOGY. 



as a whole from the same specialists. As in the case of ichthyology, only 

 a few of the numerous contributions to the branch made during the past 

 two years can be referred to. 



The systematic arrangement has been exhibited in the popular works 

 on natural history published under the names of Broun (by C. K. 

 Hoffman), Brehm, and Cassell (by H. G. Seeley). 



The skull has been examined in various stages of development by P. 

 Stohr (for Urodela), andW. K. Parker (for typical lizards, chameleons, 

 and turtles), while R. Wiedersheim has monographed the entire skele- 

 ton of a salamander — Pleurodeles, The heart and its functions have 

 been studied by M. Lourt, B. Luchsinger, and G. Siebert; and the 

 Embryology by C. von Bambeke and F, M. Balfour (for the lizards). 



New species have been described by many, E. D. Cope beiug the most 

 prominent among American naturalists, while several marine chelonians 

 have received new names from S. W. Garman. 



Various faunas have likewise received attention. O. Boettger and E. 

 Boser have attended to the Portuguese Amjjhibians and A. Tourneville 

 to the French ones, and discovered what they have considered to be 

 "new species" in those old, long-known countries. 



The Coecilians have been investigated by both W. Peters and 1\. 

 Wiedersheim ; the poisonous serpents of Europe by E. de Betta. 



The extinct species have received the attention of E. D. Cope and O. 

 C. Marsh in the United States, and in England of J. W. Hulke, E. Owen, 

 H. G. Seeley, and ^V. H. Twelvetrees. 



ICHTHYOSAURUS VIVIPAROUS. 



Within the body cavity of various Ichthyosauri small individuals of 

 the form have been several times found, and it has been generally 

 sui)posed that they had been devoured by the large ones. Professor 

 Seeley has, however, looked into the question, and has come to the con- 

 clusion that Ichthyosaurus was really viviparous. The position of the 

 small skeletons within the body is such as to make the viviparity of the 

 animal much more probable than the inclusion by swallowing. There is 

 at any rate no inherent improbability whatever in the viviparity of 

 the type. Indeed the question whether a reptile is vivii)arous or ovipa- 

 rous is of comparatively little moment, as it simply depends upon a slight 

 degree of retardation in the retention of the ova, or the inclusion for a 

 slightly longer time within the body of the parent. There is no signifi- 

 cance such as exists between the viviparity of mammals and the oviparity 

 of birds. {Academy ; also. Am. JS^at., vol. xiv, p. 00, January, 1880.) 



THE LIMBS OF MOSASAUROIDS.* 



Among the most interesting of the reptiles of the Cretaceous epoch 



* Marsh (O. C). New Cbaracters of Mosasauroid Eeptiles. A7n. Join: Science, (3,) 

 voL xiv, pp. 83-87, pi. 1. 



Owen (R.). On the occurrence of rare extinct Vertebrates found fragmentarily in 

 England. No. 3. Ann. and Mag. Xat. Hist., (5,) a'oI. v, pp. 177-181, ]}l. 8. 



