304 R. Lydekker—Oxford and Kimeridge Clay Sauropterygia. 
type is P. brachydirus, described in the previous year in the same 
writer’s ‘“Odontography.” In 1869 Prof. Seeley, in his “‘ Index to 
the Woodwardian Museum,” applied the name Plesiosaurus megadirus 
to the above-mentioned vertebral column in the Cambridge Museum ; 
merely, however, mentioning its large size and the number of the 
cervical vertebra, and the description being therefore insufficient to 
authenticate the name. A second imperfect skeleton, in the same 
collection (presented by Mr. Stead Jones), was referred to the same 
species; that specimen having a propodial of the peculiar type of 
P. trochanterius. In the following year Mr. Hulke described in the 
Q.J.G.S. vol. xxvi. the vertebral column, the pectoral and pelvic pro- 
podials, and the imperfect coracoids of a large Plesiosaur from the 
Kimeridge Clay of Dorsetshire under the name of P. Manseli; and 
also certain dorsal vertebree remarkable for their very short centra, 
to which the name P. brachistospondylus was accordingly applied. 
In the course of the description of the former species the resemblance 
of the propodials to the type of P. trochanterius was pointed out, and 
no very good reasons were given why the specimen should not have 
been referred to that species, which was thus proved to be Plesio- 
saurian. 
Gili . 
ft i ay \ Qa 
= 
Fie. 2.—Dorsal aspect of the right humerus of Plestosaurus trochanterius ; from the 
Kimeridge Claveto sama. preaxial, p, postaxial border ; e, division between radial 
and ulnar facets. (After Phillips.) 
Reference was also made to P. megadirus, which was considered to 
be closely allied, although it was stated that in the opinion of Mr. W. 
Davies it was not identical. It should be added that Mr. Hulke’s 
types are preserved in the British Museum. The year 1871 saw the 
publication of Phillips’s “Geology of Oxford,” in which work 
vertebra of large Plesiosaurs from the Kimeridgian of Oxfordshire 
were described under the names of P. brachyspondylus and P. validus ; 
the former being wrongly identified with P. brachyspondylus of 
Owen, which is really a Pliosaur, and the latter being regarded as 
new. No reference (perhaps owing to the close sequence of the two 
works) was, however, made to Mr. Hulke’ s P. Manseli; and detached 
