220 Kecords of the Indian Museum. [Wot xanie 
marked difference as regards this between the sexes. The small 
specimens M ***+** possess a fin measuring one-third of the length 
of the mantle and resemble the useful illustration of Hoyle (J. c., 
p. 156, text-fig.). Sixteen males from various hauls, with mantle- 
length of 21-97 mm., possess a fin measuring about half the length 
of the mantle, and the same proportion is shown by eleven females 
with mantle of 16-120 mm. In three females with mantle of 63- 
75 mm. the fin does not attain quite half the length of the mantle, 
and in two others with mantle of 30-42 mm. the fin measures two- 
thirds of the mantle. The largest sized specimens of both sexes 
possess a fin measuring more than half and less than one-third of 
the mantle. 
8174-91 
The rings of the arm suckers in the young specimens M **4y" 
show five to eight teeth, and some large tentacle rings possess 
sixteen to nineteen teeth round the ring; suckers occur on the 
buccal membrane but there is no trace of a hectocotylus. 
Large males, frequently, but not always, have the largest 
rings of the lateral arms larger than the largest rings of the club. 
In females these rings are almost always either slightly or much 
smaller than the largest rings of the club, and as a consequence 
of this they have fewer teeth on the lateral arm rings than the 
male owing to the smaller size of the ring. Thus a male with 
mantle of 75 mm. possesses ten or eleven teeth on the lateral 
rings, and not more than six on the dorsal and ventral arms, and 
a female with mantle of 72 mm. does not possess more than six 
teeth on the largest arm suckers. The number of teeth on the 
largest tentacle rings does not appear to increase after a certain 
mantle-length has been attained. Thus a male and female with 
mantlelength of 77 mm. possess seventeen to twenty teeth on the 
largest rings, and the same number is shown by two females with 
mantle of 120-134 mm. 
The number of suckers on the different angles of the buccal 
membrane varies from one or two to three, four or six. Five 
to nine blunt teeth are present on the ring, part of which is 
always smooth. In large females a tubercle is placed at the base 
between the ventral angles. In the small specimens M *®°*°?°®*' 
the nidamental glands are barely perceptible in females with a 
mantle-length of 10-15 mm. The smallest sexually distinct 
males have a mantle of 16mm. Young specimens of both sexes 
have much fewer chromatophores, but examples with a mantle- 
length up to about 37 mm. seem always to show two very 
conspicuous clusters of dark chromatophores on the dorsal surface 
of the head, giving each little creature a superficial appearance of 
having two eyes on the back of its head as well as the real 
laterally-placed eyes. 
- As regards anatomy the specimens M *274** were examined 
and nothing was discovered that is not usual in the genus. The 
female specimen had the ovary tightly packed with eggs—the 
bilobed nidamental gland measured 24 X 11mm, The radula 
