Vol. 63.I BASEMENT-BEDS OP THE BKISTOL COALFIELD. 467 



Pisces. 



Diplodus gibbosus, Agassiz. 



A single tooth of minute size, measuring 4-5 millimetres in length 

 by 2 mm. at the base. The median denticle is long and cylindrical : 

 the lateral denticles are compressed and divergent. 



Pleuroplax Rankxnei, Hancock & Atthey. 



A single dental plate, measuring 2 millimetres by 1 mm. The 

 carina of the dental crown is well rounded, and more obtuse at one 

 end than at the other. The several elements of the dental plate 

 are indicated by six to seven low ridges, strongest near the margin 

 and dying out just before reaching the summit of the crown. The 

 lateral wings are comparatively broad for the size of the tooth. 



Megalichthys pygsoeus (?), Traquair. 



Two very small scales, one coarsely punctate, the other smooth. 

 These are the only traces of Megalichthys that were found, although 

 the genus was diligently looked for. 



Strepsodus sauroides, Binney. 



Rather less than half of a scale of normal size, the antero- 

 posterior length being fully 17 millimetres. The ornament of longi- 

 tudinal furrows is well marked, and even coarse. They bifurcate 

 just before reaching the scale-margin. 



Khtzodopsis sauroides, Will. 



Several scales of small size and a clavicle and infraclavicle were 

 found. The maximum diameter of the scales does not exceed 

 4 millimetres, while in other coalfields they are frequently twice 

 and three times this diameter. Two small triangular bones with 

 an ornament of curved striae may possibly represent the maxillae. 



Ccelacanthtjs elegaxs (?), Newberry. 



Two scales incomplete anteriorly, 7 millimetres broad and 6 mm. 

 long, the surface covered with slightly-irregular striae which 

 converge posteriorly. 



Rbadinichthys monensis, Egerton. 



Numerous scales, averaging 2 millimetres by 1 mm. The scale- 

 ornament is well shown on most of the specimens, and consists of 

 comparatively few striae parallel to and near the anterior and in- 

 ferior borders, and a small series of more median ridges terminating 

 in six acute denticulations along the posterior border. The under- 

 surface of the scale is slightly concave, with a few relatively-large 

 punctuations. 



Elonichthys sp. 



Several small scales of typical Eloniclithys-tj\)Q, but too small to 

 identify, the largest not exceeding 3 millimetres. 



