NOTES ON CARBONIFEROUS COCHLIODONTS 25 



P. acutus differs from P. legrandensis in the posterior inner angle 

 being much more produced, in being less enrolled transversely, in 

 its greater breadth, and in the anterior and inner margins meeting 

 in a slightly more acute angle. The species is a little larger than 

 P. legrandensis. The surface of the enamel is everywhere finely 

 punctate. 



Formation and locality: Coal Measures; LaSalle, Illinois. 

 Paleontological Collection, Walker Museum, No. 10036. 



Psephodus carbonarius sp. nov. 



(Plate I, Fig. 7) 

 Type and only specimen observed, a posterior tooth. Measurements: 

 antero-lateral margin, 2o mm ; postero-lateral margin, i8 mm ; greatest breadth, 

 i9 mm . Tooth thin, strongly arched transversely and longitudinally. Trape- 

 zoidal, with antero- and postero-lateral borders about the same length. Tooth 

 highest near the anterior angle of the postero-lateral border. From this high 

 point the surface declines abruptly to the anterior angle of the posterodateral 

 border and slopes down gradually to the other borders. Surface of enamel 

 everywhere finely punctate. Lines of growth faintly impressed or absent. Mar- 

 gin not crenulate. 



P. carbonarius is readily distinguished from P. crenulatus by being 

 much more strongly arched and lacking crenulations. 



Formation and locality: Coal Measures; Newport, Indiana. 

 Paleontologic Collection, Walker Museum, No. 10032. 



Deltodus and Sandalodus Newberry and Worthen 

 That the genus Sandalodus has not been sufficiently well defined 

 to separate it from Deltodus is shown by the disagreement among 

 authors concerning the genus to which the species Deltodus grandis 

 and D. complanatus should be assigned. Newberry, who described 1 

 both genera, says 2 that D. grandis is a typical Deltodus, while St. 

 John and Worthen 3 and Eastman 4 believe that it is a Sandalodus . 

 Newberry contends that D. complanatus is a typical Deltodus, 5 while 

 St. John and Worthen 6 and Eastman 7 call it a Sandalodus. 



During the progress of the present investigation several hundred 



1 Paleontology of Illinois, Vol. II, pp. 05 and 102. 



2 Transactions of the New York Academy of Science, 1897, pp. 297 and 299. 



3 Paleontology of Illinois, Vol. VII, p. 184. 



4 Bulletin of the Museum of Comparative Zoology, Vol. XXXIX, p. 198. 



5 Op. cit., p. 102. ■ 6 Op. cit., p. 184. ^ Op. cit., p. 198. 



