NORTH STAFFORDSHIRE COAL-FIELD ORGANIC REMAINS. 319 



curved slightly upwards anteriorly, posteriorly descending more abruptly. 

 Mandible in one piece, tapering to a slender, slightly upcurved, symphysial 

 extremity. Both jaws beset with fine conical smooth teeth of two sizes, 

 the larger about three times that of the smaller, among which they are 

 set at regular intervals, and from which they are distinguished only by 

 size. Operculars narrow, elongate ; suboperculars small, square. No trace 

 of inter-operculars. Branchiostegal rays numerous, flattened, enamelled. 

 The sculpture of the cranial and facial bones consists of close-set tubercles, 

 sometimes confluent into short ridges. The occipital bones are perhaps 

 represented by large scale-like plates occurring close to the head. Pectoral 

 arch weak ; scapulars flat, articulated, not coalescent with the truncated 

 coracoids. Pectoral fins small, not lobate. Ventrals small, at middle of body. 

 Dorsal and anal small, triangular, equal, opposite ; intermediate between 

 ventrals and caudal. Tail markedly heterocercal ; upper lobe slender ; its 

 short rays entirely beneath the prolonged axis of the body. The rays of 

 the lower lobe increase in length up to the fifth or sixth, which exceed 

 the anal fin ; and thence diminish till they meet those of upper lobe at an 

 angle of 35°. The dorsal fin is preceded by a few, the upper caudal lobe is 

 covered by many fulcra! scales. The thin enamelled scales, disposed in oblique 

 series, are similar over the body, those of the upper and lower margin being 

 sbghtly smaller than those on flanks. The obliquity of their axis from the 

 production of the posterior inferior angle, gives them in situ a rhomboidal 

 appearance. The ridges are more numerous on the lower than the upper 

 half, and are not continuous across. 



This very elegant genus is nearly allied to Palceoniscus and Catopterus, 

 'Eenf., and ranks therefore with them among the Lepidosteidce. It has as yet 

 been found only in Staffordshire. Species unica Cycloptychius carbonarius, 

 Huxley. 



Specimens of a tooth, named Strepsodus, in the Jermyn Street Collection 

 and Catalogue, are frequent. This tooth, figured as Holoptyehius sauroides 

 in the Tyneside Natural History Club's Beports, has also been referred to 

 Megalichthys, but is generically distinct. It varies from three-eighths to one 

 inch in length, and is distinguished by its bayonet form, a knee-bend occurring 

 at the commencement of its distal fourth ; it is slightly curved backwards, the 

 convex surface being smooth, the concave traversed by fine parallel, longi- 

 tudinal, discontinuous ridges, which die out as they curve outwards towards 

 the anterior aspect. The pulp occupies three-fourths of the base, but is re- 

 duced to a point near the knee-bend. Seven such teeth are preserved, with 

 a fragment of a jaw, in Mr. Ward's Cabinet at Longton : the implanted equals 

 the exserted portion in length. On the same slab a scale with radial furrows 

 occurs. Teeth of the same kind are associated on a block of shale in the 

 Hunterian Museum, Glasgow, with cycloidal scales, whose free surface is 

 traversed by radiating broad grooves, large vertebral rings whose central 

 space is one-third to one-fifth of the whole diameter, flattened neural spines 

 and rounded bony spiciila, which are probably fin-rays. The form and 

 sculpture of this tooth are amphibian rather than piscine ; while neither order 

 offers any good analogy to its mode of occurrence in the jaw above men- 

 tioned. Several doubtful fragments and a deep amphiccelous vertebra suggest 

 the presence of Amphibia in the Longton district. 



A quadrilateral scale, with rounded angles, provisionally named Bhombo- 

 ptychius, HnxL, is found near Longton ; one specimen measures two square 

 inches, but is exceptionally large. The posterior smaller portion, marked off 

 by two oblique shallow grooves, is ornamented with coarse concentric ridges ; 



