REPORT ON THE CEPHALOPODA. 



169 



IS. 





40 m 



11. 







50 , 









14 , 









18 , 









10 , 









7 , 









16 









6 





Eight. 



Left. 



16-5 mm. 



16 mm 



16 



16 „ 



15 



15 „ 



15 



15 „ 





55 



jj 



45 „ 



possible to ascertain that it does not form a terminal cone like that of Ommastrephes or 

 Taonius. 



Dimensions. 

 End of body to mantle-margin, 

 End of body to eye, 

 Breadth of body, . 

 Breadth of head, . 

 Eye to edge of umbrella. 

 Length of fin, 

 Breadth of fin, 

 Breadth of each lobe, 



Length of first arm, 

 Length of second arm. 

 Length of third arm. 

 Length of fourth arm, 

 Length of tentacle. 



Notwithstanding the great distance between the localities where this species and 

 Verrill's Benthoteuthis megalojJS ^ were captured, it seems quite possible that they may 

 ultimately prove to be the same species. The chief differences seem to be the absence of 

 the angular sinus in the eyelid in the Challenger specimen, the greater comparative size of 

 the head, (though this may be explicable by the individual being smaller), and the suckers 

 on the sessile arms being for the most part in two, not in four, series ; but the two rows 

 in the Challenger specimen are very irregular, and if but slightly more so might easily be 

 regarded as four. 



Verrill has called attention to certain embryonic characters in this genus, which are 

 certainly very strildng, namely, the size and position of the fins, the short arms, and 

 more particularly the shape of the head, with the eyes situated at the anterior angles of 

 a roughly quadrate mass. 



The pen is very remarkable, exhibiting a combination of the characters of Ommastrephes 

 and Loligo ; I greatly regret that the posterior extremity was damaged in extracting it 

 so that I have been unable to depict the extreme end on the plate ; the dotted line 

 indicates what seemed to have been the original form. 



Certain other structural peculiarities of this animal seem to fit it for an abyssal 

 existence ; the small fins are in marked contrast to those of most pelagic species, 

 although some genera which are characteristic surface forms such as Cranchia and 

 Idiosepius have fins quite as small : the minute suckers and delicate tentacles appear 

 but little fitted for raptorial purposes ; while on the other hand the large circumoral 

 membrane would seem well adapted for collecting nutritive matters from an oozy bottom. 



It is uncertain to what family this form rightly belongs ; it is possible that a new one 

 wUl eventually be required for its reception. 



I Third Catal., p. 402. 



(ZOOL. CHALL. EXP. — PART XLIV. 1886.) Xx 22 



