SYSTEMATIC REVISION OF THE SUBORDER. 



57 



Dimetrodon longiramus sp. nov. (Text figures 15 and 16.) 



Cope. Name not published, but label found with a specimen. 



Type: A lower jaw and scapulae with a few vertebr£e. No. 4091 Am. Mus. Nat. 

 Hist., Cope, coll.; from Texas. 



Homeotype: No. 4136 Am. Mus. Nat. Hist., Cope, coll. A fragmentary jaw, 

 from Texas. 



The name "longiramus" was found written by Cope on a label with the 

 fragmentary jaw, No. 4136. A closely similar jaw occurs with a scapula 

 and a few vertebrae labeled D. 7'cctiformis. A lumbar vertebra, though evi- 

 dently belonging to Dimetrodon^ does not have the characters of the speci- 

 men regarded by Cope as D. rectifoTmis. 



Description : The lower jaw is very long and slender and the posterior end resem- 

 bles that of D. iiicisiviis in form, but the upper and lower edges are not expanded as 

 in that species, so the jaw is not so high behind. The scapula is very short and wide 

 compared with that of D. iiicisiz'iis and the articular face for the humerus very small. 



FOREIGN FORM. 



Ctenosaurus Koeneni v. Huene. 



Gaol, und Paleontolog. Abhdlg. Koken. N. F., Bd. vi, 

 Heft I, 1902, s. 38. 



Type : A series of vertebrse with high spines 

 gradually widening distally; preserved in a slab of 

 stone. From the upper part of the Buntersandstein, 

 east of Rheiuhausen near Gottingen. Preserved in the 

 museum of the University of Gottingen. 



Original description (adapted from a translation) : 

 "The specimens consist of several slabs carrying a 

 poorly preserved series of vertebras which have been 

 greatly compressed. One of these vertebrae with the 

 elongate spine attached measures 600 mm. in length. 

 The spines are so much compressed that the bases are 

 flat, though this may not have been the original condi- 

 tion ; the upper part of the spine is naturally flat and 

 the whole is bent and inclined to the rear. The verte- 

 brae are almost twice as long as high. The spine is 

 located over the middle of the neural arch, but the pos- 

 terior zygapophyses reach far back. v. Huene concludes that the animal is a last 

 survival of the family Clepsydropidcz which has persisted into the Trias. 



"Derartige Wirbel weiss ich mit nichts besser zu vergleichen als mit den per- 

 mischen Clepsydropidcn aus Texas und Bohmen. Der Umriss des Wirbelkorpers 

 erinnert am meisten an Naosaurus und Dimetrodon^ der Ban des oberen Bogens an 

 diese und Embolophorus. Von diesen drien aber hat Dimetrodon die grosste Aehn- 

 lichkeit. Ob die Wirbelkorper ampicol sind wie bei den Clepsydropiden ist unmog- 

 lich zu erkennen. Audi die abnorm ausbildung des Dornfortsatz ist bei Clepsydrop- 

 iden am ehesten zu erwarten, ich brauche uur an Naosannts und Dimetrodon zu 

 erinnern. Bei alledem halte ich es fur mehr als wahrscheinlich, Clepsydropiden dass 



Fig. 1 7. — Sketch ok a slab showing ver- 

 tebrae of Ctenosaurus /ioeneni, from 

 the Middle Bunter near Gottingen. 

 X /'s about. After v. Huene. 



