256 PROCEEDINGS OF THE NATIONAL MUSEUM, 



About 50 species of invertebrates are known from the Caney shale, 

 and the beds are tentatively correlated in age with the uppermost 

 Mississippian or base of the Pennsylvanian. 



CLADODUS COMPRESSUS Branson. 



For purposes of bibliographical record it may be stated here that 

 the type-specimen upon which this species is founded was named 

 Cladodus striatus in the original description.* It was pomted out by 

 the present wi'iter 2 that this name could not be used, Agassiz having 

 already appHed it to the type species of Cladodus; and in an article 

 published in Science,^ Doctor Branson proposed that it be replaced 

 by the title of C. compressus. 



Genus DICRENODUS Romanovsky. 



Syn. Carcharopsis Agassiz; Fristidadodus M'Coy. 



This genus is represented by a single species in the Mississippian 

 rocks of this coimtry, described by Newberry imder the name of 

 Carcharopsis wortheni.^ A second North American species appears 

 to be indicated by the specimen immediately to be described. 



DICRENODUS TEXANUS, new species. 



Plate 7, fig. 4. 



Founded upon a unique tooth having a total height of 2.5 cm., and 

 width at base of crown of 2 cm. In general form resembhng the type 

 of D. wortheni (Newberry), but anterior coronal face slightly concave, 

 no lateral cusps at the base, and root with deep median sinus. Cor- 

 onal margins strongly and evenly crenulated from the apex to the 

 base, and summits of the lateral crcnulations secondarily notched. 



The type and solitary known specimen of the new cladodont just 

 described is catalogued as No. 8097. It was collected by Prof. J. A. 

 Udden, of the University of Texas, in 1914, from strata of Pennsyl- 

 vanian age near San Saba, Texas, and by him presented to the Mu- 

 seum through the present writer. From the same horizon and 

 locality Professor Udden also o})tained the ichthyodroulite herein- 

 after referred to under the ca])tion of Physonemus gemmatus. 



Family PETALODONTIDAE Newberry and Worthen. 



Of this extinct family only a single genus is known, Janassa, in 

 which other skeletal parts have been foimd m natural association 

 with the dentition. No fin-spines are known to occur in this genus, 

 hence it is unlikely that such defenses were present in other members 

 of the same family. Jaekel, however, in a valuable article on the 



> 30th Ann. Rept. Dept. Geol. Nat. Resources Indiana, 1906, p. 1378. 



2 Memoir 10, N. Y. State Museum, 1907, p. 62. 



» Vol. 27, 1908, p. 311. 



< Pal. Illinois, vol. 2, ISiiH, p. G9, ])\. i, fig. 14. 



