37 



from New Jersey, L. perlatus from Alabama, and L. prariger from Kan- 

 sas, the name Nectoportlieus was proposed, and briefly characterized 

 (Extinct Batr. Eeptilia N. America, 1870, p. 208.) Prof. Marsh subse- 

 quently gave the Kansas species the name of Ehinosaurus', which name 

 being pre-occupied more than once, I changed it to Bliamplwsaurus.* 

 This name will remain for species of the type of Liodon proriger, if they 

 be found to represent a genus distinct from ISfecfoportheus or Liodon, of 

 which there is as yet no evidence. 



LiopoN MiCROMUS, Marsh ; Ehinosaurus micromus, Mar&h Amer. Journ. 

 Sci. Arts, 1872, June, tab. xiii, figs. 1-2. 



Niobrara chalk of the Smoky Hill. 



Liodon nep^olicus, sp. nov. 



RJiampliosaurus nepceolicuSj Cope, MSS. 



Kepresented by the mandibular and parts of the maxillary and pre- 

 maxillary bones, the quadrate, a dorsal vertebra, &c., of a single individ- 

 ual. These all indicate an animal related to the large L. proriger, but 

 not more than one-third the size or less. It is about the same size as 

 the X. micromus, Marsh, but is much more like the L. proriger in charac- 

 ters, so as to render it important to ascertain whether it be not a young 

 individual of that species. An examination having convinced me that 

 such is not the case, the points of distinction will be given further on. 



The premaxiUary is very prominent, forming a rostrum whose inferior 

 face is narrowed below, and then suddenly descends to a prominent 

 transverse ridge, which bounds the anterior alveoli in front. The four 

 premaxillary teeth stand on an area a little broader than long. Extrem- 

 ity broken. The anterior suture of the maxillary is vertical and zigzag. 

 It displays a lateral contraction just behind the first tooth, while the 

 anterior margin of the nostril is above the third tooth. The teeth of 

 both jaws have broadly oval bases, and apices with two cutting edges 

 and lenticular section. The inner face is more convex than the outer, 

 most so in the anterior part of the jaws, and neither is facetted. The 

 enamel is finely striate-grooved, especially toward the base. The man- 

 dible is light and thin, and diminishes in depth posteriorly. The coro- 

 noid is small, and the angle -is produced backward, and but little down- 

 ward. The rami are not complete ; the large portions preserved exhibit 

 teeth at intervals of precisely an inch. Professor Mudge, who discovered 

 the specimen, states that the jaw, when together, measured 26 inches in . 

 length, which would leave 13 inches for the dentary bone. This is, there- 

 fore, not far from the true number of teeth. 



The quadrate resembles that of L. dyspelor in various respects. The 

 internal longitudinal ridge is very prominent, and extends from the 

 proximal angle to the distal articular face, in line with the plane of the 

 short acuminate hook. The great ala is narrow and rather stout ; the 

 proximal articular face slopes steeply outward. The stapedial pit is a 

 narrow straight groove (perhaps partly closed by pressure). The knob 

 is represented by a longitudinal crest bordering the meatus below on 

 the outer side, and not continuing to the distal articulation. The sur- 



• This name was applied by Fitzinger to two species of lizards, which had already- 

 received several generic names, and hence became at once a synonym. Further, he 

 did not characterize it ; for these reasons the name was not nreoceupied at the time 

 I employed it as above ; hence there is no necessity for Prof. Marsh's subsequent name 

 Tylosaurus, given on the supposition of preoccupation. 



