214 A. Smith Woodward — On the Genus Notidanus. 



11, 12) may be referred with almost equal certainty to situations in 

 the upper jaw somewhat further back. The elongated teeth, which 

 belong to the sides of the lower jaw — and perhaps partly to the 

 upper — usually have the principal cone relatively prominent (Figs. 

 13 — 15), though in one or two examples such is not the case. 

 The anterior serrations are mostly fine and numerous, but in a few 

 instances (of upper teeth) they are reduced in number and increased 

 in size. 



Of British Cretaceous strata, the various divisions of the Chalk 

 appear to yield the most abundant remains of N. microdon, although 

 the Cambridge Greensand also affords a considerable number. The 

 National Collection comprises specimens from Maidstone, Burham, 

 and Charing in Kent ; Lewes and other localities in Sussex ; Guild- 

 ford in Surrey ; and Swaff ham and Norwich in Norfolk. 



10. N. lanceolatus, sp. nov. PL VI. Fig. 16. 



In the Egerton Collection of the British Museum there is a single 

 upper tooth of Notidanus (p. 1227) from the Gault, which it appears 

 impossible to identify with any species hitherto described. It is 

 much larger than the corresponding teeth of N. microdon, and as its 

 most conspicuous feature consists in the comparatively long and 

 narrow form of the cones, I propose to distinguish this type of 

 tooth by the provisional name of N. lanceolatus. The principal 

 cone is relatively prominent, and is preceded by two very long 

 denticles : there are three secondary cones, and the crown terminates 

 in a minute denticulation. The great development of the anterior 

 denticles renders it likely that the lower teeth were somewhat 

 similar to those of N. pectinatus, Ag., but the latter is a much smaller 

 species. 



11. N. pectinatus, Agassiz. 



1843. N. pectinatus, L. Agassiz, " Eech. Poiss. Foss." vol. iii. p. 221, pi. 36, fig. 3. 

 A species founded upon a tooth from the Chalk, about the size of 

 N. microdon, but especially differing from that form in the conversion 

 of the anterior serrations of the crown into a series of distinct 

 denticles. This type of tooth appears to be extremely rare, and I 

 have not seen any examples. 



12. N. dentatus, sp. nov. PI. VI. Figs. 17, 18. 



Among the Selachian remains in a collection of New Zealand 

 fossils sent by Dr. Hector to the British Museum in 1876, there are 

 two teeth from the Cretaceous of Amuri Bluff which are undoubtedly 

 referable to the genus Notidanus. In several respects they differ 

 from one another to a considerable extent, but an acquaintance with 

 the dentition of living Notidanidas can leave no doubt that they 

 belong to a single specific type, and that the one is an upper tooth, 

 while the other formed part of the mandibular series. 



The lower tooth, which is shown of the natural size in Fig. 18, 

 exhibits three small denticles in front of the principal cone, the first 

 being the largest and having a recurved apex, the second slightly 

 smaller with straight but backwardly-directed point, and the third 



