228 NORTH STAFFORDSHIRE COAL FOSSILS. 



over-lapping portion of the scales is thinner than the anterior. 

 This, when in situ, gives them one uniform strength and 

 smoothness. The posterior and superior margins of the 

 scale have a deep groove into which a corresponding ridge 

 in the margin of the over-lapping scale fits. Little or 

 nothing is known of the fins of Megalichthys. A specimen 

 in our collection has the pectoral fins well preserved. They 

 are lobate, L e. y the central portion of the fin is covered 

 with scales, the fin rays forming a fringe round the lobe* 

 A fine specimen from the Gubbin ironstone, at Shelton, pre- 

 sented by Mr. Garner to the Museum of Practical Geology, 

 shows the caudal fin in a fine state of preservation. 



The head (as shown by a perfect example in the author's 

 collection) was protected by bony plates of great apparent 

 strength. The snout is formed by a curved bone. The 

 orbits are small, circular cavities, placed high and forwards : 

 one is well shown in our specimen. On the under side of 

 the head there are two jugular plates ; along their margins 

 there are a number of lateral jugular plates. Both scales 

 and head bones are covered with a strong coating of ganoine, 

 and are ornamented with close-set minute punctures. The 

 teeth of Megalichthys are of two kinds : those in the outer 

 dentary margin of the maxilla and premaxilla are small and 

 smooth. Behind these there are larger teeth covered with 

 fine parallel stria3. The mandibular teeth are large, conical? 

 smooth teeth, with short, deep, longitudinal depressions at 

 the base (see plate, fig. 10). The outer dentary margin 

 is set with small conical, smooth, close-set teeth. Of the 

 endoskeleton of Megalichthys, good specimens of vertebra3 

 are frequently found. They arc small osseous rings, generally 

 found separated. Occasionally we find a number of them 

 united with the ossified neural arches in situ-. 



