248 
ACTIXOPTERYGII. 
Gyroclus navicularis , T. C. Winkler, Archiv. Musee Teyler, 
vol. iv. (1874), p. 30, pi. ii. figs. 19-21.—Middle Eocene 
(Bruxeliian); Uccle, Brussels. [Hot Pycnodont.] 
Gyrodus quadratus , A. E. Beuss, Yerstein. bohm. Kreideform. 
pt. i. (1845), p. 9, pi. iv. figs. 56-61.—Cenomanian; 
Bohemia. 
Gyrodus rucjidosus , L. Agassiz, Poiss. Foss. vol. ii. pt. ii. (1844), 
p. 235, pi. Ixix. a. fig. 16.—Cenomanian; Regensburg, 
Bavaria. [RoyaljBohemian M useum. Prag ueJ] 
Gyrodus runcincttus , L. Agassiz, ibid. pt. i. (1833), p. 16, pt. ii. 
(1844), p. 236, pi. Ixix. a. fig. 19.—Form, and loe. un¬ 
known. [Stuttgart Museum.] 
Gyrodus wannerius , A. Dollfuss, Faune Kimm. Cap De la Heve, 
(1863), p. 35, pi. i. figs. 17, 18 (name said to have been 
originally given by Lesueur to a jaw much resembling 
G. jurassicus , figured on a rare plate “ Yues et coupes 
de la Heve,” 1843).— Kimmeridgian ; Normandy. 
Genus STEMMATODUS, Heckel. - 
[Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. 
1856, p. 202.] 
Trunk deeply fusiform, not produced at the caudal pedicle. Head 
and opercular bones tuberculated; teeth with an apical indent 
surrounded by a crenulated margin ; vomerine teeth in five longi¬ 
tudinal series, andsplenial teeth in three series. Neural and haemal 
arches of axial skeleton of trunk not expanding sufficiently to encircle 
the notochord. Ein-rays delicate, spaced, and articulated in the 
dorsal and anal fins; stouter, more closely articulated, and divided 
distally in the caudal fin. Pelvic fins present; dorsal and anal 
fins low, acuminate in front, fringe-like behind, the former occupying 
at least the hinder half of the back, and the latter somewhat shorter, 
arising more posteriorly ; caudal fin with straight or slightly ex¬ 
cavated hinder margin. Scales covering only the anterior half of 
the trunk in advance of the median fins. 
Stemmatodus rhombus (Agassiz). 
1839-44. Pycnodus rhombus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. 
p. 188, pi. lxxii. figs. 5-7. 
1856. Stemmatodus rhombus , J. J. Heckel, Denkschr. k. Akad. Wiss., 
math.-naturw. Cl. vol. xi. p. 202. 
1856. Stemmatodus rhomboides, J. J. Heckel, ibid. p. 205, pi. ii. 
figs. 9-11. [Nearly complete fish; Royal Bohemian Museum, 
Prague.] 
