﻿510 ACTINOPTERIGll. 



Genus GYROLEPIS, Agassiz. 



[Poiss. Foss. vol. ii. pt. i. 1833, pp. 6, 172, and ibid. pt. ii. 1844, 



p. 285.] 



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 striae and tubercles. Fins well developed, with small fulcra. 

 Rays 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 

 W. Dames \ who also interprets one specimen as proving the fusion 

 of the pair of infraclavicles in the median line. 



Gyrolepis albertii. 



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 (? 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. 285. 

 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 varias, C. G. Giebel, Fauna der Vorwelt, Fische, 



p. 181 (in part). 

 1851. Gyrolepis albertii, H. von Meyer, Palaeontogr. 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 Pakeont. Abhandl. vol. iv. (1888), j.t, 2. 



