20 IOHTHYOPTBKYGIA. 



is probable that this specimen belongs to 1. campylodon or 

 an allied species. Purchased, 1859. 



Some of the following specimens may belong to Ophthalmosaurus. 



35323. The basioccipital of a very large individual ; from the Cam- 

 bridge Greensand. The transverse diameter is 0,115. 



Purchased, 1859. 



44159. A smaller basioccipital ; from the Cambridge Greensand. 



Purchased, 1873. 



44159 a. A slightly smaller basioccipital ; from the Cambridge 

 Greensand. Purchased, 1873. 



35301. A very similar basioccipital ; from the Cambridge Green- 



sand. Purchased, 1859. 



35390. A basisphenoid, agreeing in size with the preceding spe- 

 cimen ; from the Cambridge Greensand. Purchased, 1860. 



35323. The quadrate of a very large individual ; from the Cam- 

 bridge Greensand. Purchased, 1859. 



35272. The associated quadrates of a smaller individual ; from the 

 Cambridge Greensand. Purchased, 1858. 



35415. The conjoint atlas and axis vertebras of a comparatively 

 large individual ; from the Cambridge Greensand. 



Purchased, 1860. 



35302. A smaller example of the same elements; from the Cam- 



bridge Greensand. Purchased, 1859. 



35431. A very similar specimen in a rolled condition ; from the 

 Cambridge Greensand. Purchased, 1859. 



35345. A rather smaller specimen of the same bone; from the 

 Cambridge Greensand. Purchased, 1859. 



39256. The slightly imperfect conjoint atlas and axis vertebra? ; 

 from the Gault of Folkestone. This specimen agrees very 

 closely with No. 35302. Purchased, 1865. 



47275. A considerably smaller and more imperfect example of the 

 corresponding bone ; from the Folkestone Gault. 



Gardner Collection. Purchased, 1876. 



32814. One half of the centrum of a dorsal vertebra of a large in- 

 {Fig.) dividual ; from the Lower Chalk near Dover. Figured by 



