jAinjAET 29, 1909] 



SCIENCE 



195 



otiohus group and one other. The Pariotichus 

 group is ordinally but not closely related to Pro- 

 colophon. They were low, clumsy, crawling rep- 

 tiles, large headed, with very primitive skull con- 

 struction, pectoral girdle very primitive except 

 for absence of cleithrum, 22-24 thoracic vertebrae, 

 no intereentra, imperfectly double-headed ribs, 

 some ventral armature, and very primitive, flat, 

 plate-like pelvis. The phalangeal formula is not 

 yet proved; there is no evidence as yet of the 

 chelonian formula in any Permian reptile, and it 

 is probably derived from the older formula with 

 more numerous phalanges; the cervical vertebrae 

 are short and few in number; the animal had 

 practically no neck, as in the contemporary am- 

 phibians. The characters of Lysorophits have 

 been stated in a recent publication by Dr. Willis- 

 ton; an important discovery is of evidence that 

 it possessed completely formed limbs, although of 

 small relative size. 



Discussion: Dr. E. C. Case observed in regard 

 to the abdominal ribs of the Pariotichidse, that 

 they were present in certain specimens discovered 

 by him last summer. The absence of intereentra 

 was confirmed and its significance considered. The 

 essential similarity, aside from a few highly spe- 

 cialized characters, of all these Permian forms as 

 noted by Dr. Williston, is only explainable as a 

 retention of primitive characters. 



This paper was followed by " Notes on a Col- 

 lecting Trip in the Permian of Texas, during the 

 Summer of 1908," by Dr. E. C. Case. The author 

 discussed the stratigraphy and conditions of depo- 

 sition of the Texas red beds. No very satisfac- 

 tory arrangement of these strata has yet been 

 made. Professor Cummins's earlier arrangement 

 was into (1) Wichita, (2) Clear Fork, (3) Double 

 Mountain, successively overlying the Albany lime- 

 stones, the Clear Fork being the chief fossiliferous 

 horizon. The first two divisions are not clearly 

 separable in Dr. Case's opinion. The succession in 

 the part of the region studied by him was as 

 follows : 



(4) Conglomerate and sandstone layer similar 

 to that below. 



(3) Red clay, about 20 feet. 



(2) Conglomerate layer, varying to a cross- 

 bedded sandstone. 



( 1 ) Red clays. 

 The upper conglomerate forms the top of the 

 country in the eastern part of the region. The 

 sandstone is composed of aeolian sand, the con- 

 glomerate of rather angulate pebbles. West of 

 Dundee the upper and lower conglomerate mem- 

 bers come together and at the junction is a heavy 



bone bed. West of this comes in a new conglom- 

 erate layer. The strata were regarded as deposited 

 along a lagoon-coast into which were washed the 

 remains of animals and sediment from the dry 

 land. They are not, strictly speaking, estuarine. 

 Little is yet known of the geographic or geologic 

 distribution of the fauna. The genus Diplocaulus, 

 abundant north of the Wichita, has not been found 

 south of it. Remains of insects — two well-pre- 

 served wings — ^were discovered by Dr. Case last 

 summer, their first discovery in this fauna. Other 

 interesting discoveries were a new reptile of small 

 size and a new amphibian allied to Zatrachys or 

 Aspidosaurus. 



Discussion: Dr. Williston inquired whether the 

 author considered that these beds indicated arid 

 climatic conditions. Dr. Case: The beds them- 

 selves probably not, but the back country may 

 have been arid; the bones occur chiefly in the con- 

 glomerate; in the clays they are very rare, but 

 when found are apt to be articulated skeletons. 

 This fauna was at least in part made up of dry 

 land animals; the construction of the feet in 

 Dimetrodon and Naosaurus is evidence for this 

 view. 



Dr. Gordon took some exception to the author's 

 explanation of the stratigraphy, and discussed the 

 relations of the sandstone layers. Dr. Williston 

 observed that his experience last summer con- 

 firmed the general accuracy of Dr. Case's stratig- 

 raphy, but that river channels appeared to be 

 more abundant; he illustrated a typical example 

 which he had noted. 



Dr. Gordon further discussed the paper, point- 

 ing out that the so-called Permian red beds of 

 this region are in fact a northward continuation 

 of the Albany limestone itself, instead of an over- 

 lying formation. This had been suspected by 

 Dr. Cummins himself in the later years of his 

 work. 



Dr. David White discussed the relations of the 

 plants of the formation and its geological age. 

 In his opinion, it is probably Permian and not 

 Carboniferous. The evidence of aridity did not 

 seem very convincing. Dr. Gordon: As originally 

 applied the Clear Pork and Double Mountain 

 formations do really overlie the Albany. The mis- 

 take in Dr. Cummins's stratigraphy lay in his 

 extending the Clear Fork eastward into Baylor 

 County. 



The president then called for the paper by 

 Dr. Dean. 



The author showed a series of micro-photo- 

 graphs illustrating the remarkable preservation 

 of the muscular tissue in the fossil sharks of the 



