OPHIOPSIS. 



71 



which all the fins except the anal are nearly complete. In this fossil the ring- 

 vertebrae are sufficiently stout not to have collapsed by crushing-, and thus form a 

 ridge beneath the squamation. The pectoral fin is strengthened at the base of its 

 foremost ray by two or three large fulcra which rapidly increase in length back- 

 wards. The pelvic fin is relatively large and fringed with conspicuous fulcra. The 

 dorsal fin, which rises to a sharp eminence in front, has five or six basal fulcra 

 increasing in length ; and its fringing fulcra do not extend to the distal end of the 

 foremost ray. The position of the very small anal fin is indicated, and this fin is 

 restored from other specimens. The fork of the caudal fin is well shown. The 

 large postclavicular scales are nearly smooth, but apparently serrated at their 

 hinder border. Some of the anterior flank-scales are not only serrated, but also 



Fig. 25. — Ophiopsis procera, Agassiz; restoration, about two-thirds nat. 6ize. — Lower Kimmeridginn (Lithographic 

 Stone) ; Bavaria. Based chiefly on a specimen in the British Museum (no. P. 6939). 



marked with pectinations extending from the serrations. The lateral line is incon- 

 spicuous, only indicated by an occasional short vertical slit or a postero-inferior 

 notch on the scales which it traverses. Along the base of the dorsal fin, small 

 irregular triangular scales are intercalated at the upper ends of the transverse 

 series. The only enlarged ridge-scale is a flat oval scale at the beginning of the 

 fulcral series on the dorsal border of the caudal pedicle. 



1. Ophiopsis penicillata, Agassiz. Plate XVI, figs. 1, 2. 



1844. Ophiopsis penicillata, L. Agassiz, Poiss. Foss., vol. ii, pt. i, p. 290, pi. xxxvi, figs. 2 — 4. 

 1895. Ophiopsis penicillata, A. S. Woodward, Catal. Foss. Fishes B.M., pt. iii, p. 169. 



Type. — Nearly complete fish ; British Museum. 



Specific Characters. — A robust species about 18 cm. in length. Length of head 



