39 
labelled by bim S. favosns in tlie Egerton collection leaves no 
donbt as to wliat he meant. Under the circumstances, how¬ 
ever, Sauvage’s name claims priority. This Curtodus Rigauxi 
is doubtless founded on the lateral teeth of Agassiz’ Strophodus 
favosus. The description he gives of the species is as 
follows :—‘‘ Dents de grandeur moyenne, ovalaires, plus renflees 
a la partie moyenne qu’ aux laterales, en dos d’ane. Les 
reticulations de la surface semblent rayonner de la partie la 
plus elevee, formant une serie de mailles atfectant la forme 
lozangique en haut, beaucoup plus allongees vers la racine. 
Les pores sont larges, mais deviennent beaucoup plus etroits 
en s’ approchant de la couronne : celle-ci est separee du reste 
de la dent par un leger bourrelet d’ ou partent des reticulations 
verticales. 
Cette espece, le type du genre, donnee par Bouchard au 
musee de Boulogne, provient du Bathonien de Marquise.” f 
Though Sauvage’s genus Cusfodus cannot now be accepted, 
his specific name stands, and we must substitute Strophodus 
Rigauxi for Strophodus favosus* But as the description given 
by Sauvage refers to teeth of the 5th and 6th rows (counting 
from the median plane of the jaw) it must, obviously, be sup¬ 
plemented by descriptions of the median and infra-median 
types. These descriptions, which I shall proceed to give, are 
founded on specimens in the Egerton collection labelled by 
Agassiz Strophodus favosus —which specimens are now in the 
British (Natural History) Museum. Two median teeth are 
thus labelledf (one, however, with a query) : in general 
character they strongly resemble the borresponding teeth of 
S. magnus^ but differ from them in their ornamentation, the 
ridges being stronger but not so markedly radiating (some, 
indeed, are almost parallel). These ridges are most marked 
near the crown : the tooth is almost punctate near the margin. 
There is only one tooth of the third row; this is rhomboidal 
* Poiss. foss. des form, sec. du BoulL, p. 53, and pi. III., figs. 7 and 7a. 
There is a woodcut of S. favosus in “ Science Grossip ” for May, 1885, in 
one of a series of interesting papers by A. Smith Woodward, on Fossil Sharks 
and Rays. Any one desiring a clear and concise summary of our present 
knowledge on the subject should read these papers. 
f The median teeth in the British Museum collection labelled S. favosus by 
the Earl of Enniskillen are S. magnus. 
