92 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
LIST OF SPECIES OF CTENACANTHUS OCCURRING IN THE 
MISSISSIPPIAN SERIES (continued). 
NAME OF SPECIEs. 
Kinderhook. 
Burlington 
Keokuk, 
St. Louis 
6. C. sculptus St.J.and W. . . X 
7. C. semicostatus (St. J. and W.) x 
8. C. solidus Eastm. , des x 
9. C. spectabilis St. J. and w.. ch Me x}/—|/—|—|— 
xX 
»¢ 
10. C. varians St. J. and W. 
11. C. venustus Eastm. . — 
12. C. (*%) burlingtonensis St. J. sina w. —} xX|/—J]—|— 
18. C. gradocostatus St.J.and W.. . | =| X | — 
14, °C aeutus Masti oj oe is5) a).5 bs ee ee 
15. C. cylindricus Newb. . . . - . |—|—| % 
16. C. excavatus St. J.and W.. . . ee a eee 
17.0: Keone Sted. an WW ee oe —|}—| xX 
» 4 
18. C. siphias (St. J.and W:) .) 1.) < —|— _— 
19. C. costatus N.and W.. . . . . | m—J— X 
20. C. deflexcus St. J.andW. . . . |—|—|—| *X 
21. C. gemmatus St. J.and W.. . . |—|—|—j] X 
22. C. gurleyi Newb. . . wee | —foy—]| xy — 
23. C. harrisoni St. J. and w. - 2. | —f—o}—| xX 
4, C.hitoni Newb. . «ss se | ee Xx 
25. C. pellensis St. J.& W. . « «© © | —|—}]—)} XI] — 
26. C.angulatus N. and W. . ... |—|—|—|—| X 
27. C. canaliratus St. J.and W. .-. |—}]—/—]—| X 
. C. similis St. J. and W. . x 
III ON ACANTHODIAN REMAINS FROM THE COAL 
MEASURES OF MAZON CREEK, ILLINOIS. 
Representatives of the Acanthodii are extremely rare in the Palzozoic 
rocks of North America, and the only species hitherto described are 
restricted to the Devonian of the United States and Canada. If we 
neglect the detached spines of Macheracanthus, and the indetermin- 
able mass of scales described by Dr. J. M. Clarke’ as Acanthodes() 
pristis, American Acanthodians are limited to but one species each of 
1 Bull. U. S. Geol. Survey, No. 16 (1885), p. 42. 
