Cope.J ^ ' 4: |- Feb 3> 



ius, a genus only known as yet from cranial remains. With present knowl- 

 edge the reference of the 1. oMensis to the latter genus is inadmissable. The 

 cranium, thoracic region, and fore-limbs of IcJithycanthus are unknown. 



Char. Specif. The centra of the dorsal vertebrae are about as long as 

 deep, and their sides are deeply concave : there are four anterior to the 

 pelvis which are without ribs . The caudal vertebrae are robust, and seven 

 from the first, support a small tubercule-like diapophysis. The chevron 

 bones are short and acuminate ; the neural spines are a little shorter, nar- 

 row and truncate, and directed backwards at the same angle as the chevron 

 bones. They are much reduced on the eighteenth caudal vertebra, where 

 the chevron bones are considerably longer. 



The abdominal rods are quite slender. The hind limb is quite stout for 

 this order. The femur is regularly expanded at both extremities, but the 

 distal is deeply and openly grooved, distinguishing the condyles, while the 

 proximal' end is plane. There is no trochanter visible. The ulna and ra- 

 dius are well separated, and are three-fifths the length of the femur. There 

 is a large fibu lare tarsal bone of a subquadrate outline. In immediate con- 

 tact with it is the probably external digit with five phalanges or segments ; 

 the ungual is simply conic. The femur is as long as five dorsal vertebrae. 

 The ribs have expanded, undivided heads, and extend to the abdominal 

 armature. 



Measurements. M. 



Length of last ten dorsal vertebrae 047 



" first twenty -three caudal vertebrae 117 



' ' a posterior rib 029 



" " dorsal vertebra 005 



" twenty-second caudal vertebra 005 



"femur 025 



Proximal diameter of femur 008 



Width of lower leg 009 



Length of fibula 015 



" " tarsal bone 006 



"digit 027 



This salamander is about the size of the Menopoma allegheniense. 



ICHTHYCANTHUS PLATYPUS. Sp. nOV. 



This batrachian is represented by almost the same portions of the skele- 

 ton as the preceding species, furnishing a good basis of comparison . It is 

 very well preserved, displaying the characters especially of the hind foot, 

 which is almost entirely represented. 



Several features distinguish it from the I. oMensis, one of which is of 

 more than usual value if correctly indicated by the fossil. There are ten 

 vertebrae from anterior to the sacrum preserved in place, and none of them 

 supports a rib, nor are there any ribs visible anywhere on the block of 

 shale. I suspect that they exist on more anterior vertebrae, or may have 

 been displaced to a more anterior position than they normally occupy. 



