104 
NAUTILOIDEA. 
costae are directed obliquely backwards, and cross the septa at an 
acute angle, passing across the periphery and forming a shallow 
sinus in the middle. None of the specimens in the British-Museum 
Collection have the test preserved, so that the ribbing has only been 
observed upon casts. The costae are equally well developed upon 
the body-chamber and upon the septate part of the shell in the 
adult, but they were either very feeble or altogether absent in the 
young. 
Fig. 14. 
Ephlppioceras costatum . — Ventfal or peripheral view of a cast showing the 
coarse ribbing, some of the septa, and the greater part of the body- 
chamber. Drawn from a specimen in the Collection. Natural size. 
Remarhs. It is due to my friend NTr. G.C. Crick to observe that it 
was he who pointed out to me the costate eharacter of the surface of 
this species, which I had overlooked. Indeed, the costm are more 
easily felt than seen, and unless the specimens are held in a certain 
direction as to the light these ornaments might very easily escape 
attention. In the drawing they naturally appear plainer than in 
the specimens, though their prominence has not been exaggerated 
in the slightest degree. 
The difference between this species and E. ditellariuin has 
already been pointed out, but it may be added that the latter has 
a broader periphery than E. costatum. 
Horizon. Coal-Measures. 
Localities. Madeley, Coa|brookdale, Shropshire ; Martley, Mor- 
eestershire. 
Well represented in the Collection. 
