ON THREE INTERESTING NEW OEGOPSIDS FROM THE BAY OF SAGAMI. i^g 
tinuous along the whole length, but is divided into three pieces : the fore- 
most of oval shape, is the smallest, the middle is the longest, stretching from 
a little behind the anterior mantle-margin to about the level of the middle 
of the fin, and the last is about eight times as long as the first, and does not 
reach the extreme end of the mantle but is one length distant from it. 
Under the skin of the paler maculae on the head, is also found the same 
substance as seen in the paler zones on the mantle, but it is a little thicker and 
is transversely oblong. Such substances of the mantle, as well as of the 
head, are all situated in the depressions of the muscles at those places, and 
the skin covering them is a little thicker than that covering the remaining 
parts (PI. IV, fig. 12). 
The principal differences of the present species from .S". onalanicnsis 
(Lesson), with which it stands in the nearest relationship, are as follows : 
1. Luminous organ absent. Hectocotylised left ventral arm much 
thicker and longer than right ventral arm, with 14 suckers and broad protec- 
tive membranes greatly thickened ; about 3/5 of the distal part of whole length 
is bare but only with a narrow longitudinal ridge. Horny ring of largest ten- 
tacular suckers with a large tooth in each of 4 corners and 5 small teeth bet- 
ween each larger succeeding 2 Symplectoteiithis oiialaiiiensis (Lesson). 
2. Luminous organ present. Hectocotylised left ventral arm a little 
shorter than right ventral one, and as thick as the latter, and provided with 
about 24 normal suckers along proximal part; protective membranes as broad 
and thick as those of right arm ; distal 1/3 of whole length not bare but with 
34 minute tubercles each on a swollen base. Horny rings of largest tentacular 
suckers with only a large tooth on upper-most edge 
Syinplectotciitliis lumiiiosa sp. nov. 
