190 



LABYRINTHODONTIA. 



Trimerorhachis insignis, Cope 

 The type species. Length of skull about 0,160 (6*3 inches) ; 

 length of intercentra 0,010 (0*4 inch); the latter dimensions 

 indicating an animal about one third the size of Eryops mer/a- 

 cephalus. 



Hab. North America (Texas). 



R. 576 x. The basioccipital region of the cranium, a fragment of 

 the mandible, and four vertebrae ; from the reputed Per- 

 mian of Texas. These specimens agree in all respects 

 with the corresponding elements represented in fig. 46 ; 

 the neural arches retain, however, their proper relative 

 position to the intercentra. Purchased, 1885. 



Pig. 46. 



Trimerorhachis insignis. — a, occipital region of cranium ; b, mandibular articu- 

 lation ; c, posterior view of the same; d, part of the vertebral column, with 

 the neural arches crushed down ; e, another portion of the vertebral column. 

 From the reputed Permian of Texas, ^. P, pleurocentrum ; i, intercen- 

 trum. 



R. 574. Two fragments of jaws probably belonging to this species ; 

 from Texas. Purchased, 1885. 



R. 574 x. Three imperfect bones, apparently associated with the 

 preceding ; from Texas. The expanded bone is probably 

 part of the pectoral girdle, while the other two specimens 

 appear to belong to the limbs. Purchased, 188")'. 



1 Proc. Amer. Phil. Soc. vol. xvii. p. 524 (1878). 



