scombrim:. 
475 
a nd loss deeply implanted at the base ; small outer teeth forming a 
cluster at the mandibular symphysis. 
Form. $ Loc. Middle Oligocene (Rupelian) : Rupelmonde, 
Belgium. 
Not represented in the Collection. 
Scombramphodon crassidens, sp. nov. 
1844. Sphyrccnodus crassidens, L. Agassiz, Poiss. Foss. vol. v. pt. i. 
p. 99 (name only). , _ , . _ 
1890. Dictyodus (?) crassidens , Woodward & Sherborn, a . n . 
Foss. Vert. p. 64 (name only). 
Type. Fragments of jaws ; British Museum. 
Apparently closely similar to S. curvidens, but the apices of the 
teeth less incurved, and the teeth on the anterior half of the 
dentary less regularly arranged. 
Form. <$■ Loc. Lower Eocene (London Clay) : London Basin. 
B- 1779. Abraded fragments of jaws in matrix showing the large 
teeth with plicated bases, labelled by Agassiz an 
intended to be the type specimen of this species ; Sheppej . 
Eyerton Coll. 
P - 158. Fragmentary head ; Sheppey. The cranium seems to have 
considerably resembled that of Scomber and Scombrinus, 
but is deeper and more laterally compressed. The pre- 
maxilla is long and slender, not much expanded in front. 
It bears a single series of large teeth, which are deeply 
plicated in their basal half and not incurved at the apex. 
The hinder portion of the right dentary exhibits traces 
of the outer series of small teeth. Purchase , 
38945. Anterior half of left dentary, showing bases of teeth, rather 
irregular in arrangement, clustered on the symp jsis , 
Sheppey. Each tooth has a very small pulp-cavity. 
11 ' Jiowerbank Coll. 
B- 1780. Hinder portion of small left dentary and premaxilla ; 
Sheppey. The bases of the two scries of mandibular 
. J , Eyerton Coll. 
teeth are shown. J 
28755. Imperfect small head, doubtfully of this species ; Sheppey 
Purchased , 1853 . 
38907. Smaller imperfect head, doubtfully of this species. 
Bowerbank Coll. 
