510 
ACTIXOPTERYGI1. 
Genus GYROLEPIS, Agassiz. 
[Poiss. Foss. vol. ii. pt. i. 1833, pp. 6, 172, and ibid. pt. ii. 1844, 
p. 285.1 ^ 
Trunk elongate-fusiform. Mandibular suspensorium oblique ; 
dentition comprising an irregular series of well-spaced conical lani- 
aries ; opercular apparatus narrow, the operculum being especially 
deep ; all the external head and opercular bones finely ornamented 
with striee and tubercles. Fins well developed, with small fulcra. 
Fays bifurcated, those of the pectoral fins stout and unarticulated, 
except at their distal extremities; pelvic fins longer than deep; dorsal 
fin triangular and elevated, arising in advance of, but partly opposed 
to, the anterior portion of the much extended anal; [caudal fin 
unknown.] Scales of moderate size, narrowed ventrally, and not 
much deepened on the flank; externally ornamented with striations. 
The foregoing definition is based upon the researches of 
AV. Fames \ who also interprets one specimen as proving the fusion 
of the pair of infraclavicles in the median line. 
Gyrolepis albertii.* Agassiz. 
1835. Gyrolepis albertii, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 173, 
pi. xix. figs. 1-6. 
1835. Gyrolepis tenuistriatus, L. Agassiz, ibid. p. 174, pi. xix. figs. 10, 
11 (P fig. 12). 
1835. Gyrolepis maximus , L. Agassiz, ibid. p. 175, pi. xix. figs. 7-9. 
1837. Gyrolepis tenuistriatus, H. B. Geinitz, Beitr. Kenntn. Thiiring. 
Muschelkalkgeb. p. 21, pi. iii. fig. 4. 
1843. Gyrolepis tenuistriatus , J. E. Portlock, Rep. Geol. Londonderry, 
p. 469, pi. xiv. fig. 11. 
1843. Gyrolepis albertii , J. E. Portlock, ibid. p. 469, pi. xiv. figs. 12-14. 
1844. Gyrolepis albertii, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 2b5. 
1844. Gyrolepis tenuistriatus, L. Agassiz, ibid. p. 285. 
1844. Gyrolepis maximus, L. Agassiz, ibid. p. 285. 
1844. Gyrolepis albertii, Meyer & Plieninger, Beitr. Palaeont. Wiirttem- 
bergs, p. 109, pi. xii. figs. 40, 45. 
1844. Gyrolepis tenuistriatus, Meyer & Plieninger, ibid. p. 109, pi. xii. 
figs. 41, 43, 44, 46-48, 75. 
1848. Colobodus varius, C. G. Giebel, Fauna der Yorwelt, Fische, 
p. 181 (in part). 
1851. Gyrolepis albertii , H. von Meyer, Palasontogr. vol. i. p. 196. 
1851. Gyrolepis tenuistriatus, H. von Meyer, ibid. p. 196. 
1864. Amblypterus decipiens, F. von Alberti, Ueberbl. Trias Alpen, p. 209. 
1 Pakeout. Abhandl. vol. iv. (1S88), pt. 2. 
