ICHTHYOSAURUS. 37 



specimen may indicate a form closely allied to or identical 

 • with I. entheciodon or I. leptospondylus. 



Presented by Count Stephano de Stephani, 1882. 



46804. The right articular bone of the mandible of a large indivi- 

 dual ; from Wiltshire. The corresponding bone is seen 

 in situ in the undetermined skull, No. 49203, mentioned 

 under the head of the Acutirostrine subgroup (p. 72). 



Cunnington Collection. Purchased, 1875. 



45908. A similar specimen from the left side : from Weymouth. 



Purchased, 1874. 



41979. A broken articular of the right side : from Weymouth. 



Purchased, 1870. 



32701. The anchylosed centra of the atlas, axis, and third cervical 

 vertebrae of a large individual : from the Oxford Clay 

 Vaches Noires (Calvados), France. The suture between 

 the atlas and axis is completely obliterated, and the facet 

 for the cranial intercentrum is united with that for the 

 intercentrum between the atlas and axis. 



Tesson Collection. Purchased, 1857. 



R. 32. The centrum of an anterior cervical vertebra of a medium- 

 sized form ; from the Kimeridge Clay of Sweaton, Lin- 

 colnshire. The upper costal facet was placed entirely on 

 the arch ; as in the cervicals of the imperfect skeleton 

 from the Oxford Clay mentioned by Seeley on p. 110 of 

 his ' Index to Aves &c. in Cambridge Museum,' under the 

 name of /. megalodirus. It has a strong general resem- 

 blance to the cervical of /. hildesiensis figured by Koken 

 in the ' Zeitschr. deutsch. geol. Ges.' vol. xxxv. pi. xxiv. 

 fig. 1. Purchased, 1880. 



40551. The centrum of a slightly larger and somewhat later cervical 

 vertebra ; from the Kimeridge Clay of Weymouth, Dorset- 

 shire. Sharp Collection. Purchased, 1876. 



32704. The centrum of a cervical vertebra, very similar to No. 

 It. 32 but rather later in the series ; probably from the 

 Kimeridge or Oxford Clay of Vaches Noires (Calvados), 

 France. Perhaps associated with No. 32701. 



Tesson Collection. 



