416 MEMOIRS OF THE CARNEGIE MUSEUM. 



38. Hypsocormus macrodon (Wagner). (Plate LXXI, figs. 1 and 2.) 



(For sj^nonymy cj. A. S. Woodward, Cat. Foss. Fishes Brit. Mus., Pt. Ill, p. 394.), 



Two representatives of this species occur in the collections of the Carnegie 

 Museum, both of large size and well-preserved, and both on exhibition in the 

 Hall of Fossil Vertebrates. One, having a total length of about 65 cm., is pre- 

 served without any distortion other than vertical crushing, and displays the head- 

 parts and all the fins in very nearly their entirety. The other, which is more 

 than twice the size of the first, is contorted in such manner that the body is coiled 

 upon itself, the head and inferior caudal lobe being closely approximated. The 

 relatively short head, with its large, forwardly placed orbit, together with the 

 slender and elongate form of body, terminating in a widely expanded caudal fin, 

 give to this species a characteristic expression. The bones of the head are finely 

 tuberculated, and the scales delicately striated. The ventral fins are situated 

 midway between the pectorals and anal fin. To this species may also be referred 

 an imperfect detached head, cataloged as number 4794. 



• 



Genus Asthenocormus A. S. Woodward. 



39. Asthenocormus titanius (Wagner). 



(For synonymy c/. A. S. Woodward, I. c, Pt. Ill, p.' 380.) 



Of this species, one of the largest of Jurassic Pachycormidse, only two tolerably 

 complete individuals are known, the holotype which is in Munich, and the inter- 

 esting specimen studied by Vetter, which belongs to the Dresden Museum. In 

 neither specimen is the dentition satisfactorily shown, nor is any trace preserved 

 of the pelvic fins. Nevertheless there is reason to believe that the latter organs 

 were present, and that a series of enlarged prehensile teeth was borne anteriorly 

 by the jaw-parts. Such, at least, are among the characters which have been ob- 

 served in the case of the next following species. 



Mention should be made in this connection of a peculiar structure described 

 by Vetter in the example studied by him, the significance of which would seem to 

 have been misinterpreted. The position of the stomach and intestinal tract 

 is clearly indicated in the specimen belonging to the Dresden Museum and according 

 to the author just named, the intestine is provided posteriorly with a remarkably 

 well-developed spiral valve. The small diameter of this tube, its tapering posterior 

 extremity and total absence of coprolitic matter in its interior, are features difficult 

 to reconcile with the view that we here have to do with a much convoluted spiral 

 valve. A more plausible interpretation is to regard it as a calcified air-bladder 



