132 
M. SASAKI. 
Fig. 1. — MelcagroUuthis separata sp. nov. 
ventrnl aspect with luminous organs 
in approximate position. 
The mantle is of a conical shape, 
broadest a little back from the anterior 
mart^in, and the length is about one and a 
half times greater than the breadth ; the 
dorsal anterior margin projects a little 
into an obtuse angle in the middle. The 
fins are .semicircular, extending a little 
backwards beyond the posterior end of the 
mantle, and their length is a little shorter 
than half the mantle-length (text-fig. i). 
The head is large, and broader than 
the mantle-opening, and it is clearly mark- 
ed from the neck by a boundary edge, the 
ventral part of which shows a low arch 
bounding a shallow siphonal groove. 
The eyes are very asymmetrical, the 
eye-opening as well as the eye-ball of the 
left side being twice or more greater than 
those of the right side in diameter. On 
each side of the neck there is a low trans- 
verse ridge with an olfactory papilla. The 
siphon is short and conical, connected with 
the siphonal groove, by two pairs of dorsal 
ligaments somewhat submedian in posi- 
tion. The siphonal resisting cartilages 
are nearly oval in shape, being a little 
acuminated anteriorly, with an elongate 
deep median depression; the nuchal carti- 
lage is lanceolate, a little tapering posteri- 
orly. The mantle cartilages corresponding 
with the siphonal ones are high and linear 
