PISCES. 27 



the tooth, by a slightly trenchant crest to which the lines on the enamel converge." 

 From the Cornbrash of Le Wast, near Boulogne. 



Description. — A single tooth in the collection of Mr. "VValford is referred to this 

 species. It has a very polished surface ; the diameter at the base of the enamel is 

 13 mm. and the length 27 mm. Its section is circular, and it is slightly curved — 

 160 very fine ridges may be counted at the base. These are discontinuous, and 

 fresh ones, fewer in number, take their place, nearer the apex, being about 75 half- 

 way up. Where the curvature begins to increase near the apex the ridges become 

 very short, irregular in outline, and join here and there to their neighbours. The 

 median line of the curved surface is raised on both sides into a larger crest, com- 

 parable, however, with the rest ; it commences half-way up, and becomes stronger 

 as it crosses the apex. The smaller ridges, as long as they remain linear, converge 

 to it at their upper end, but do not join it. 



It will be seen that this tooth is in absolute agreement with the type, but the 

 small details of ornament which separate it from the species called M. interruptus, 

 found in the Kimericlge Clay of the same locality (Sauvage, M. S. G-. F., ser. 2, 

 vol. x, no. ii, p. 51, pi. iii (vii), figs. 7, 8) are such as might well be due to 

 difference of development in the jaw of the same species, in which case the latter 

 name would have the priority. 



Distribution. — The only specimen is from the railway station at Handborough. 

 It may be well to note that other species of the same genus from the Stones- 

 field Slate are represented in the British Museum. 



Class PISCES. 



No skeletons of fishes are known from the Cornbrash, not even any naturally 

 associated hard parts, all the fossils of the class consisting either of teeth or spines. 

 The following have been recorded : 

 *Astekacanthus acttus (15, 63, 65). *Steophodus MAGNUS (42, 62, 65). 



* ornatissimus. * — ■ iugauxi (60). 



* — verrucosus (42). — subreticulatus (42). 

 *Pycnodus Bucldandi (42). * — tenuis (63, 65). 



Asteracanthus ornatissimus. — The entry of this fish represents the belief that 

 certain teeth belonged to the type called Strophodus subreticulatus, and that this 

 type belonged to the spine thus named. The same teeth have been otherwise 

 determined as Strophodus tennis, and if this be accepted the spine theoretically 

 belonging to the other tooth is lost with it. Only one spine is known. 



Asteracanthus verrucosus — an erroneous determination of the identical spine 

 called Asteracantlms acutus. 



Strophodus subreticulatus teeth are now determined as S. tennis. 



