J. W. HULKE ON POIKILOPLEURON BUCKLANDPI. 
18. Nore on Porxtnorrevron Bucktanpi of Euprs Drstonecuamrs 
(pére), IDENTIFYING i¢ with Mueatosaurus Bucxianpr. By 
J. W. Hurxe, Esq., F.R.S., F.G.8. (Read February 5, 1879.) 
[Puare XII.] 
One difficulty, and not the least, which besets the student be- 
ginning to study fossil reptiles is the great embarrassment occa- 
sioned by the not unfrequent description of the same reptile under 
different names, involving the worse than merely useless multi- 
plication of genera and species. Wherever, then, the identification 
of a newer with an older genus can be established, entailing, as it 
should, the abandonment of the newer generic name, it is to be 
looked on as a positive gain. I now submit to the criticism of the 
Geological Society the evidence which appears to me to identify 
beyond reasonable doubt Potkilopleuwron Bucklandi of Eudes Des- 
longchamps, pcre, with an older acquaintance, Megalosawrus 
Bucklandt. 
The literature of Pokilopleuron is, fortunately, not extensive. 
The following list comprises all the principal papers relating to the 
genus which I have found, arranged according to priority of pub- 
lication :— 
I. “ Mémoire sur le Potkilopleuron Bucklandi, grand Saurien fossile, 
intermédiaire entre les Crocodiles et les Lézards, découvert dans 
les carriéres de la Maladrerie, prés de Caen, au mois de juillet 
1835.” Par M. Eudes Deslongchamps. Mém. de la Soc. Linn. 
de Normandie, vol. vi. p. 36, pls. ii.—vii. (1838). 
II. “ Report on British Fossil Reptiles.” By R. Owen. Brit. Assoc. 
Report, 1841, pp. 84-88. 
III. “ Contributions to the Anatomy and Taxonomy of the Dino- 
sauria.” By T. H. Huxley. Quart. Journ. Geol. Soc. 1869, 
XXV1. pp. 28-34. 
IY. Poikilopleuron valens. Contributions to the Extinct Vertebrate 
Fauna of the Western Territories. Part i. pp. 279 and 338, 
pl. xv. figs. 16-18. By Dr. J. Leidy. 1873. 
VY. Poikilopleuron pusillus. Supplement vii. to the Monograph on 
Fossil Reptilia of the Wealden and Purbeck Formations, in 
Pal. Soc. vol. 1876, p. 1, pl.1. By R. Owen. 
The remains of the large Saurian which Deslongchamps re- 
covered from building-materials obtained from a quarry near Caen, 
and reconstructed, after months of patient labour, with sufficient 
completeness for their skeletal determination, comprised :—a score of 
vertebrae in two series, all caudal ; a humerus and two bones, which 
he regarded as radius and ulna (but which a comparison of his 
excellent figures of them with metatarsals of Dinosaurs clearly 
shows to belong to the hind foot); parts of a tibia and fibula; an 
