GEOLOGICAL SUKYEY OF THE TEKEITOEIES. 635 



Pappichthys plicatus, Cope, spec. noY. 



Established on a series of bones of the skull and vertebree. Tlie cranial 

 bones are deeplj' grooved, and with parallel ridges between. The outer 

 face of the dentary is roughly grooved on the inferior half of its posterior 

 two-thirds. The inner face is marked by a strong groove near its middle 

 to the symphysis, above which it is very convex; below it extends to a 

 thin edg-e. The dental alveoli are shallow and in close contact ; there 

 are six m .025''^ at its middle, where it is also .019 deep. The teeth be- 

 come smaller at the symi^hysis. The maxillary bone is rod-like proxi- 

 mally, but flattens out much distally, and is there slightly rugose on the 

 outer face. The teeth are smaller than the mandibulars, there being 

 at the middle fourteen in .025"'. The alveoli are larger proximally. The 

 depth of the bone at the beginning of the suture for the supplementary 

 maxillary is .020"^. The superior extremity of the hyomandibular is 

 broad and flat. The inferior quadrate is thickened behind, and has a 

 sublongitudinal condyle distally. The squamosal suture of the ptery- 

 goid adjoins it. 



Kuiuber cranial ridges in .010™, 10. The vertebrse preserved are 

 quite short, and have sessile diapophyses ; they are broader than deep. 

 Width, .026°'; depth, .019; thickness, .005. The articular surfaces for 

 the neural arches are confluent, so as to have a subquadrate outline. 



Another specimen is represented by numerous fragments. One of 

 these is the proximal half of the os maxillare. This extremity rises in a 

 curve, is somewhat depressed, and is excavatfed below. The inner face 

 is very convex, the outer flatter and with squamosal suture for premax- 

 illary external to the extremity a half inch. A fragment of the j)alatine 

 exhibits a series of large marginal teeth and a plate of smaller ones 

 within them, thus resembling Amia ; the superior face exhibits a deep 

 longitudinal groave, which opens out posteriorly. The prooticbone is a 

 half disk, thickened on the straight edge, and with concave sides, with a 

 flat tuberosity on one of them. On some of the cranial bones the ridges 

 are interrupted. The dorsal vertebrae of this specimen have the centra 

 broader than deep, and with projecting diapophyses. The neural ar- 

 ticular faces are for its own arch and that of the next vertebra, and there 

 are two narrow grooves on the inferior face. They are nearly or quite 

 distinct. As this is observed on vertebroe with elongate diapophyses, 

 and they are confluent, or one is wanting on those with sessile diapophy- 

 ses, it is probable that the position of the neural arches is shifted on 

 the dorsals, an arch being confined to a single centrum on the posterior 

 ones, as occurs on the caudals only in Amia calva. 



The specimens came from distinct localities on Cottonwood Creek. 



Pappichthys scleeops, Cope, sp. nov. 



Established on a ramus of the mandible of one, and other similar 

 specimens of other individuals. These indicate a large fish, equal 

 in size to the alligator-gar of the Mississippi. The dentary bone is 

 more compressed and deeper than in P. plicatus. The longitudinal 

 groove runs above the middle line, and the portion of the bone below 

 it thins to an edge. The upper portion is thi(;kened, and the alveolar 

 border is wide and bounded by an angle on the inner side. The alveoli 

 are large and shallow; in .025"^ scarcely three find place. Near 

 the symphysis is a smaller one, which is separated by a considerable 

 diastema from the succeeding one, (perhaps abnormally.) The external 

 face of the bone is rough and somewhat tubercular. 



