OSTEOLEPIDJE. 
373 
Osteolepis ncina , E. von Eichwald, Bull. Soc. Imp, Nat. Moscou, 
vol. xvii. (1844), p. 831, and ibid. vol. xix. (1846), pt. ii. 
p. 308, and Leth. Bossica, vol. i. (1860), p. 1555, pi. lvii. 
fig. 9 ; L. Agassiz, Poiss. Eoss. V. G. B. (1845), p. 155 ; 
C. H. Pander, Saurodipt., Dendrodont. &c. devon. Syst. 
(1860), p. 7.—Devonian ; Marjina. [Mandibular ramus: 
University of St. Petersburg. Scales from L. Carboniferous 
Limestone of Podmokloye, Govt. Toula, also doubtfully 
ascribed to this species.] 
Osteolepis tscherskyi, J. Y. Bohon, Mem. Soc. Acad. Imp. Sci. St. 
Petersbourg, [7] vol. xxxvi. no. 13 (1889), p. 13, pi. ii. 
figs. 32-35, 39, 41.—Devonian; Yalley of Kisil-kul, 50 
versts W. of Minusinsk, Govt, of Tomsk, Siberia. [Scales, 
&g. : Imperial Academy of Sciences, St. Petersburg 1 
O-sA. ***** Tr/—* fit/ 
Genus T1SUKSIXJS ? Traquair. 
[Geol. Mag. [3] vol. v. 1888, p. 516.] *'»*'/** 7. p., f 
Head as in Osteolepis and Diplopterus. Dorsal fins opposed to ’ 
the pelvic pair and the anal fin, respectively. Tail strongly hetero- 
cereal ; caudal fin obliquely truncated posteriorly. Scales smooth 
and punctate. 
Thursius macrolepidotus (Sedgwick & Murchison). 
1829. Dipterus macrolepidotus, Sedgwick & Murchison, Trans. Geol. 
Soc. [2] vol. iii. p. 143, pi. xvi. fig. 2 (P figs. 4, o). 
1835, Dipterus macrolepidotus, L. Agassiz, Poiss. Foss. vol. ii, pt. i. 
p. 115, pi. ii. fig. 4. 
1855. Diplopterax macrolepidotus, F. M‘Coy, Brit. Palteoz. Foss, 
p. 587 (in part). 
(?) 1860. Osteolepis, C. H. Pander, Saurodipt., Dendrodont. &c. devon. 
Syst. p. 9, pis. i.-iii. (in part). 
1888. Thursius macrolepidotus, B. H. Traquair, Geol. Mag. [3] vol. v. 
p. 516. i / 
Type. Small fish ; Mus. Geological Society of London. 
The type species, attaining a maximum length of about 0*25. 
Head with opercular apparatus occupying one-fifth of the total 
length; jaws much elongated ; operculum deeper than broad, sub- 
operculum smaller and broader than deep. Pelvic fins situated 
about halfway between the hinder margin of the operculum and 
the extremity of the tail; first dorsal fin much smaller than the 
