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413 



Undina (?) barroviensis, A. S. Woodward. 



1890. Undina barroviensis, A. S. Woodward, Ann. Mag. Nat. Hist. [6] 

 vol. v. p. 436, pi. xvi. fig-. 5. 



Type. Fish, wanting paired fins ; British Museum. 



An imperfectly definable species, known only by the specimen 

 mentioned below. Fin-rays not expanded distally, with more 

 widely-spaced articulations than in the typical species ; principal 

 caudal fin consisting of about 16-18 rays above and below. Scales 

 ornamented with few, large, irregular, elongated tubercles, some- 

 times subdivided transversely. 



Form. § Log. Lower Lias : Barrow-on-Soar, Leicestershire. 



21335, P. 3343. Type specimen, in counterpart, described and 

 figured, loc. cit. Purchased, 1847, and Ennislcillen Coll. 



The specimens mentioned below probably indicate an undetermined 

 species of Undina, as remarked by the present writer in Proc. Geol. 

 Assoc, vol. xi. (1890), p. 292 :— 



P. 4277. Pterygo-suspensorial bone figured, loc cit. pi. iii. fig. 6 ; 

 Stonesfield Slate, near Oxford. Ennislcillen Coll. 



P. 3793. A more imperfect example of the same bone ; Stonesfield 

 Slate. Ennislcillen Coll. 



P. 4277 a. Jugular plate, resembling a specimen figured by C. Pre- 

 vost, Ann. Sci. Nat. vol. iv. (1825), pi. xviii. fig. 20. 



Enniskillen Coll. 



Genus LIBYS, Miinster. 

 [Neues Jahrb. 1842, p. 45.] 



Fin-rays broad and robust, often expanded, and closely articulated 

 in the distal half ; the preaxial rays of the first dorsal and caudal 

 fins granulated. Parafrontal and circum orbital bones with a regular 

 series of very large, broad vacuities or superficial excavations ; scales 

 ornamented with irregularly disposed, elongated tubercles. 



This genus is closely related to Undina, and was first elucidated 

 by 0. M. Reis (Palaeontographica, vol. xxxv. 1888, p. 37.). The 

 vacuities or excavations in the parafrontal and circumorbital bones 

 probably imply a large development of the mucus-secreting follicles 

 of the sensory canals. 



