30 Colorado College Studies. 



imprint of the middle and distal parts of five anterior rays of 

 the anal tin, indicates that the spine as well as the rays fol- 

 lowinyj it were articulated, and i)reserves distally some of the 

 fibres of four post-spinal dissected rays. The vertebni? have 

 fallen to the ventral surface, the corrosion of which has dis- 

 played their approximate form and size in molds. The pos- 

 terior borders of the scale-prints usually present one or more 

 shallow, rounded emarginations. 



On Plate I is given a diagram of the osteology of the 

 skull, based on the Bradbury specimen. Both the arrange- 

 ment of the bones and their morphological interpretation as 

 indicated in this diagram, are to be regarded as provisional. 

 The more or less weathered-otf and broken or scaled-oflp con- 

 dition of the crauiarbones in the Bradbury specimen, is such 

 that it is impossible to be sure that the arrangement indi- 

 cated in the diagram is entirely correct; but it is believed to 

 be at least nearly so. The position of the posterior part of 

 the parieto-occipital suture is not satisfactorily shown on the 

 specimen, but the surfaces of stone which were apparently 

 covered with the parietals are feebly elevated, and the faintly 

 defined inner-posterior boundaries of these slightly raised 

 areas are indicated in the diagram by dotted lines, as probable 

 approximate limits of the parietals. The bone called par- 

 ethmoid should possibly be called the prefrontal. On the 

 other hand, a prefrontal may perhaps be included as the an- 

 terior part of the bone called sphenotic. The latter bone 

 presents uncertain indications of being crossed by a jagged 

 suture just anterior to the position represented on the dia- 

 gram by the letters S2)h. If this suture is really present, the 

 posterior and anterior bones into which the one here pro- 

 visionally called sphenotic would so be divided, may be 

 respectively either sphenotic and postfrontal or postfrontal 

 and prefrontal. 



Family PELECORAPID/E. 



Type-genus, Pelecorapis Cope. 



Teleosts of a generalized type, combining characters of 

 the families Exocojtidte, Clupeidte, Albulida^, etc.; gill-arches 



