150 GANOID FISHES OF THE CARBONIFEROUS FORMATION. 



Secondly, in the general smoothness of the scales and absence of the scnlpture 

 characteristic of Bh. Macconochii. 



Thirdly, in the presence of some amount of denticulation of the posterior borders of 

 the flank-scales. 



There is no other known species with which Bit. Isevis can be confounded. 



Geolo(jical Position and Locality. — From the Calciferous Sandstone Series at Tarras 

 Foot, Eskdale (Collection of Geological Survey of Scotland). 



12. Rhadinichthys Grossarti, Traqnair. Plate XXXIII, figs. 7, 8. 



Rhadinichtiiys Grossarti, Traquair. Proc. Roy. Pliys. Soc. Ediub., vol. iv, 1878, 



p. 2i4. 

 — — ■ A.S.Woodward. Cat. Foss. Fishes Brit. Mus.,pt. ii, 



1891, p. 469. 



Specific Characters. — Attaining a probable length of somewhat over 2 inches ; 

 form slender ; fins few-rayed ; rays with distant articulations ; scales marked externally 

 by from four to six sharply defined straight ridges, passing from before backwards with 

 a slight obliquity, and terminating posteriorly in denticulations of the hinder margin. 



Description. — The material for the description of this little fish is as follows : 



(1) The type specimen collected by the late Mr. Grossart, surgeon, Salsburgh, 

 Lanarkshire, and now in the Royal Scottish Museum. 



(2) Two specimens from Crossford, Lanarkshire, collected by Mr. R. Dunlop, who 

 presented one of them to the above-named institution. 



(3) Fragmentary specimens in the Collection of the Geological Survey of Scotland. 

 The type specimen (PI. XXXI II, fig. 7) measures 1^ inches as it lies, but it is 



deficient in the head and anterior part of the body. The shape is slender, its depth at 

 the ventral fin being not quite \ inch, from whicii it tapers to a very delicate tail-pedicle. 

 The pectoral fin is not seen; the ventral is small, and consists of a few delicate and 

 rather disturbed rays. The dorsal conmiences very slightly in front of the anal, and 

 consists of fourteen or fifteen rays, but in the anal I count only ten. Between the 

 latter and the lower lobe of the caudal there is a considerable interval, equalling nearly 

 three-fifths of an inch. All these fins are very delicate, with slender distantly articu- 

 lated rays ; minute fulcra are observable on the anterior margin of the dorsal in the 

 specimen under description and of the anal in another; the caudal body-prolongation is 

 very slender and attenuated. The scales are moderate, may, indeed, be called large 

 in proportion to the small size of the fish. They are more strongly marked than in 

 Bh. monensis, their ornament (fig. 8) consisting of from four to six sharply defined 

 straight ridges passing from before backwards, with a slight obliquity over nearly the 

 whole exposed surface, and terminating in denticulations of the posterior margin ; 



