HYLOSTOMTD^E. 203 



Seeleya pusilla, Eritsch \ 

 The type and only described species ; total length 0,023 (0-9 

 inch). 



Hah. Europe (Bohemia). 



R. 343. Electrotype from a fragment "of shale, showing the entire 

 skeleton. The original is-the type, and was obtained from 

 the Gaskohle (Lowest Permian) of Nyfan (Pilsen) ; it is 

 figured by Fritsch in his 'Eauna der Gaskohle,' pi. xl. 

 fig. 1. Purchased, 1882. 



Genus RICNODON, Fritsch \ 



Eody short, with a relatively large parabolic skull, of which the 

 bones are marked by minute pits. The pectoral limbs nearly as 

 large as the pelvic. Denticules on the parasphenoid and pterygoids- 

 Scutes large, with thickened posterior border. 



Ricnodon trachylepis, Eritsch 3 . 

 Imperfectly known ; distinguished from R. copei and R. dispersus, 

 Eritsch, by the characters of the scutes. 

 Hah. Europe (Bohemia). 



R. 374. Electrotype from a fragment of. shale, showing the ventral 

 scutes. The original is one of the types, and was obtained 

 from the Gaskohle (Lowest Permian) of Nyfan (Pilsen) ; 

 it is figured by Eritsch in his 'Eauna der Gaskohle/ 

 vol. i. pi. xliv. fig. 13. Purchased, 1882. 



Genus ORTHOPLEUROSAURUS, Lydekker (n. now.). 



Syn. Orthocosta, Fritsch 4 . 



Neural spines of vertebree longer than in Seeleya, and the ribs 

 short and straight. 



Orthopleurosaurus microscopicus (Eritsch 5 ). 

 Syn. Orthocosta microscopica, Fritsch 6 . 



The type and only described species. Very minute. 

 Hah. Europe (Bohemia). 



1 Fauna der Gaskohle, vol. i. pt. iv. p. 165 (1883). 



2 Ibid. p. 167. 

 s Ibid. p. 170. 



4 Ibid. pt. i. p. 28 (1879).— Hybrid. 



5 Log. cit. — Orthocosta. 



6 Loc. cit. 



