146 REVISION OF THE PELYCOSAURIA. 



microdiis has such a plate associated with the other bones and is the single other specimen of Naosaurus 

 which has any portion of the skull associated with it. It was originally called Edaphosaurus nucrodus by 

 Cope If this association is a true one, as seems certain, the name Naosatirus must be given up, as it is 

 preoccupied by Edaphosaurus and the subfamily Naosaurince of this paper will disappear and the members 

 will be placed in the family Edaphosaurida;. 

 Family : Edaphosauridce. 



E. pogonias, E. microdus, E. cruciger, E. claviger. 



It may seem that there is undue hesitancy in uniting the two genera on the evidence cited, but to any 

 one familiar with the occurrence of bones in the Texas beds the possibility of accidental association is so 

 evident that the greatest conservatism seems the best course. The original specimen of E. microdus is a 

 mass of broken bones collected from the surface and there is no history of the specimen preserved; the 

 evidence rests almost entirely on the last one (bearing the Field Number loi Coll. of E. C. C). To me it 

 seems extremely probable that the two genera must be united. 



This materially alters our conception of the character of Edaphosaurus (Naosaurus). We recognize 

 that the long-spined forms were specializing toward a diet of shell-fish and crustaceans, perhaps even toward 

 a herbivorous &\&< {Edaphosaurus). as well as toward a purely carnivorous diet and predatory nature 

 {Dimetrodon). The suggested relationships with Placodus are somewhat strengthened, as the long-spined 

 Ctenosaurus occurring so close to Placodus may have had a dentition similar to that of Edaphosaurus 

 {Naosaurus). 



Naosaurus cruclg:er Cope (page 60). 



Characteristic specimens: No. 4003 Am. Mus. : The type. No. 4004 Am. Mus. 

 Nat. Hist., Cope, coll. : A skull labeled by Cope N. cruciger. No. 4080 Am. Mus. 

 Nat. Hist, Cope, coll. : A collection of mixed and broken spines and vertebrce closely 

 similar to 'the type in appearance and matrix. No. 4004 : The skull labeled by Cope 

 as belonging to N. claviger is uncleaned, but presents no recognizable differences from 

 the skull of Dimetrodon. 



No. 4003 : No considerable portion of the type specimen can be put together, 

 so little can be made out of its general fonn. The isolated vertebral centra strongly 

 resemble those of N. microdus, but the fragments of spines show that above the first 

 pair the transverse processes were not developed beyond simple nodular rugosities, 

 never extending more than 10 mm. from the spine. The first pair is not over 20 mm. 

 long, no longer than the spine is thick at their point of origin. The processes alter- 

 nate 'above the first pair, as described by Cope, but the oblique arrangement on several 

 adjacent vertebrae mentioned by him does not hold. 



One spine shows a large medullary cavity near the base. This does not occur 

 in the other species, but its presence or absence may be due in large measure to the 

 accidents of fossilization. 



No. 4072 : In 1888 Cope published a figure of a spine which he called N. cruciger, 

 but it is very different from the type, resembling N. microdus much more closely. 



Naosaurus microdus Cope (page 60; plates 28 and 32). 

 Edaphosaurus microdus Cope, page 61. 

 Characteristic specimens: No. 4014 Am. Mus.: The type (plate 32). No. 4060 

 Am. ]\Ius.: Homeotype: A nearly perfect vertebral column from the third (?) cervical 

 to the second or third caudal, twent>'-nine vertebrte in all. It is probable that two or 

 three posterior lumbars are lost. The specimen was exceptioually carefully collected 

 for the time and the methods then prevailing. The vertebrae were numbered as taken 

 up and a small sketch accompanied the specimen showing their position when found. 

 This, and the fact that many of the vertebra: are in connection, makes it possible to 

 give a nearly complete description of the column. From Paint Creek, Hardeman 

 county, Texas. No. 4037 Am. Mus. Nat. Hist., Cope, coll. : A clavicle, vertebral 

 spines, humerus, and terminal phalange ; from Texas. 



