Fossil Fishes from Dumfriesshire. 493 



Mesopoma, gen. nov. 



Body fusiform, suspensorium only very slightly oblique, 

 but the maxilla shaped as in typical Palseoniscidai. Dorsal 

 fin nearly opposite the anal. 



I propose to separate from the genus Canobius the species 

 pulchellus {op. cit. p. 51) and politus (op. cit. p. 53), on 

 account of the more typically JPaleeoniscid configurafion of 

 their facial bones. I should have included them in Rhadin- 

 ichthys were it not for the very slight obliquity of the suspen- 

 sorium, which excludes them from the definition of the genus 

 along with another species from the Pumpherston oil-shales, 

 which I recently described as Rk. macrocephalus *. These 

 species will therefore in future stand as Mesopoma pulchellum, 

 2)olitum, and macrocejjhaluvi. 



MesoJepis tuherculatus^ sp. n., Traq. 



Of this I have seen no really complete specimens. Such 

 as have occurred show a small deep fish, about 4 inches in 

 length and 2 in depth, with a large head occupying about one 

 third of the entire length. From the structure of the head, 

 so far as it is seen, the position of the dorsal fin which com- 

 mences at the culminating part of the back, and the shape of 

 the scales, which are high and narrow, there can be no doubt 

 as to the species being referable to Mesolepis. The scales 

 differ from those of any known species in being ornamented 

 externally with a sharply defined tuberculation, the tubercles 

 often tending to become confluent transversely. 



Locality. Glencartholm, Eskdale. Type in Edinburgh 

 Museum. 



Mesolepis has not hitherto been recorded from strata below 

 the horizon of the Millstone Grit. 



Mesolepis rhombus^ sp. n., Traq. 



Length 5 inches; depth of body just in front of dorsal fin 

 2^ inches ; length of head contained a little more than three 

 times in the total. Dorsal fin commencing at culminating 

 point of back, high in front, then falling away to a fringe 

 which ends close to the tail-pedicle ; anal fin short-based, 

 triangular, acuminate ; caudal deeply cleft, heterocercal. 

 Ventral fins small ; pectorals not seen. Scales rather small, 

 narrow, their surface ornament badly preserved, but appa- 

 rently consisting of rounded tortuous ridges, sometimes 

 passing into tubercles, whose direction is mainly parallel with 

 the anterior and posterior borders of the scale. Dentition 

 not visible; head conformable to the type of Mesolepis. 



* Proc. Roy. Soc. Ediub. lor 1880-90, p. ;JU8. 



