220 A 



More complete speciiiicns ol' species of tliis genus sliow that vertebrae 

 of the type which 1 have described (p. 240) unth-r the name of Anogmius 

 belong to them.* The latter name may be used for this genus should it be 

 ascertained that our species cannot be included in the one typified by the 

 European Paclnjrhi:odi(s hamlis, Dixon. 



The posterior half or more of the cranium of a species allied to the 

 P. lathnentuiu is preserved, witli both the ma.xillary l)one and teeth, and the 

 basioccij)ilal element separated from its connections, adherent. Al)ove, the 

 latter exhil)its two subtriaiigular articular faces in clo.se contact, for the e.xoc- 

 cipitals. Below, there is a strong median carina, or crest, which is strongly 

 grooved on the free margin; this groove probably represents the muscular 

 tul)e. The exoccipital facets stand on a horizontal triangular face; l)ul, in 

 front of this, the sides of the bone are beveled to the jdane of the base, l()r 

 sutural adaptation to the prootic, etc. 



The structure of the superior walls of the skull may be largely discerned 

 in this specimen. The cranium is flat and wide, and pressure has probalily 

 somewhat increased the effect in this instance. Exoccipital, supraoccipital, 

 epiotic, pterotic, parietal, and frontal bones are clearly distinguishable; l)ut 

 there are points at which the sutures are obscure. The i)est defined are the 

 epiotics, which are subtriangular bones, presenting the apex inward, and 

 bearing a small round facet for the supratemporal on the posterior angle. 

 The pterotics and postfroutals may be easily distinguished from adjoining 

 bones, but not so well from each other. They have a thin outer margin, 

 and their upper surface is marked by bands of irregular small fossa?, and an 

 obtuse, longitudinal ridge. The middle line of tlie skull is occupied i}y the 

 supraoccipital. Its proximal portion probal)ly separates the e.xoccij)itals, 

 but this is not certain. It extends well forward, and the line of separation 

 from the frontal is not well defined. Its anterior part has a massive trans- 

 verse elevation, which sends a short median process backward, producing a 

 T-shaped l)ody; the frontal suture is proljably in front of this. The supra- 

 occipital is contracted beiiind this body, and its postero-exterior suture pre- 

 sents a remarkable peculiarity in u straight and wide truncate articular 

 face. This is opposed l)y a corresponding face of the parietal bone; the 

 latter is of an irregular t()rm, and carries on its outer portion next the pterotic 



• As suggested Proceed. Amer. Philos. Soc., 1872, p. 355. 



