378 Reviews — Dr. Anton Fritsch — Permian Fauna of Bohemia. 



external border of the orbit, excluding the jugal, meeting the pre- 

 frontal in front, and the post-frontal, squamosal and supra-temporal 

 behind. The jugal is greatly elongated, reaching forward with the 

 maxillary to the anterior angle of the nasal bones, and backward 

 to the end of the maxillary bone behind the orbit. The parietal 

 bone is remarkably small, being only one-fifth the length of the 

 skull. The epiotic bone terminates posteriorly in a blunt point. 

 The supra-temporal bone is very large, and forms nearly a third of 

 the hinder part of the skull. The qaadrato-jugal is longer than the 

 supra-temporal, and margins it externally. The condition of the 

 condyle is not quite clear, but the condyle is apparently bilobed, 

 and there is no evidence that the basi-occipital enters into it. In the 

 lower jaw there were 25 to 30 slender teeth, with farrows at the 

 base. 



The vertebi'al column includes 23 vertebrae in the thorax, two in 

 the sacrum, and about 35 to 40 in the tail. The large hypocentrum 

 of the vertebra is constricted in the middle like a dice-box, and is 

 deeply cupped for the unossified part of the notochord. The pleura- 

 centra are small ossifications at the sides, seen in both the thoracic 

 and caudal vertebrge. Below these ossifications, and between the 

 hypocentra, are small hypocentra-pleurale. In the caudal vertebrae 

 these latter ossifications appear as inferior spinous processes. The 

 author traces the modifications of these vertebral elements in the 

 several regions of the vertebral column; and shows that the pleura- 

 centrum in the caudal vertebrae of this genus is not placed between 

 the hypocentrum and neural arch, as in the figure of Euclnrosaurus, 

 given by Gaudry, but is jDlaced between two neural arches, in a way, 

 we may remark, that becomes more intelligible from Professor Hasse's 

 researches on Elasmobranch fishes. The author is disposed to appeal 

 to the keeled leaf- shaped inferior processes of the vertebrae as throw- 

 ing light upon the keels in the caudal vertebrae of crocodiles. But 

 those processes might be appealed to in elucidation of the chevron 

 bones ; and the keels on the crocodilian caudal centrum are readily 

 comprehended as the longitudinal extension of the chevron facets 

 consequent upon the increase in size of the vertebra with age. 



The ribs are thickened at the proximal end, without definite 

 capitulum and tuberculum, rounded and flattened at the distal end, 

 and never longer than four times the length of the vertebra. In 

 the sacral region the ribs become transformed into powerful 

 transverse processes like those seen in Melanerpeton and Splieno- 

 saurus, and comparable to the structures seen in young crocodiles 

 and Chelydra serpentina. 



The clavicle is a long stalk-shaped bone placed anterior to the 

 coracoid. The coracoid is expanded, subtriangular, with a posterior 

 stalk process. Between the coracoids is the rhombic-shaped inter- 

 clavicle. In the restoration a scapula is shown extending dorsally 

 over the ribs. 



The fore arm is shorter than the upper arm. There are five digits 

 in which the number of bones is 1, 2, 3, 2, 1. The pelvis consists 

 of three boues on each side, which are united into an os innominatum, 



