REPORT ON THE CEPHALOPODA. 



Dimensions 













Length, total, ........ 113 mm. 



End of body to mantle-margin, . 











84 



„ 



End of body to eye, 











78 



„ 



Breadth of body, . 











37 



„ 



Breadth of head, .... 











40 



,, 



Eye to edge of nmbrella, . 











18 



„ 



Breadth of fin. 











8 



„ 



Diameter of largest sucker on sessile arm, . 











1 





Diameter of largest sucker on tentacle, 











0-6 



, 



Length of shell, .... 











90 



, 



Breadth of shell, .... 











29 



, 



Right. 



Left. 



Length of first arm.i . . . . . . .23 mm. 



22 mm 



Length of second arm, 









22 „ 



20 „ 



Length of third arm, 









20 „ 



20 „ 



Length of fourth arm, 









23 „ 



22 



Length of tentacle, . . . 









8C 



„ 





This species is of special interest because it has hitherto been known only from a 

 shell in the Zoological Museum at Copenhagen, which was the only specimen then 

 known to possess the peculiar ridged spine shown in fig. 11. Eecently, however, I 



Fig. 5. — Shell of Sepia mestus, Gray, from the type specimen in the British Museum labelled " Sep. mestus. 

 Australia, Presented by Dr. Sinclair, E.N." Drawn by Mr. P. J. Smit. 



happened to notice that the tyjjc of Gray's Sejna mestus was similarly armed, but 

 being then unable to make a thorough investigation of the matter, I sent the Challenger 

 specimen to my friend Mr. Edgar Smith who was good enough to institute a comparison 



1 The lengths of the arms are measured from the oral margin. 



