1916.| A... Massy: Cephalopoda of the Indian Museum. IgI 
Polypus aculeatus (d’Orbigny). 
Octopus aculeatus, d’Orbigny, Céphalopodes acétabuliféres, p. 53, pl. 7, 
fost 201525) 5) ple omit dtyn ple 23, HSS..3, 4:(1338): 
M £19. Investigator,’ 25-vili-1g11, Byikhwaaw Bay, Burma, Marine 
Survey of India—One ¢. 
M £243=7 (2?) Burina (W. 7. Blanford) from coral reef—Five ¢. 
These are characterized by a short body, narrower head, and 
arms about seven times the length of the mantle. The umbrella 
is highest laterally, attains from one eighth to one-tenth of the 
length of the arms, and continues on their outer margins almost 
to the tip, forming wide membranous expansions. The mantle 
opens midway between the eye and the siphon, and on a line with 
the base of the eye. Siphon conical, with a narrow opening, free 
for about half its length, and reaching above the level of the eyes ; 
funnel organ, in the only specimen examined, W-shaped, and dark 
red on a pale ground; hectocotylized arm relatively long, with a 
wide membranous sperm canal; terminal organ small, narrow, 
with crenulated edges folded over the transversely-grooved inner 
channel. Some suckers on the lateral arms are moderately 
enlarged. 
One specimen has had four of its arms mutilated near the 
base, a sharply-projecting point indicating the commencement of 
a new limb in each case. Very large cirri occur on the head and 
near the eyes in all the specimens, and are dispersed also on the 
dorsal surface of the mantle and umbrella and on the proximal parts 
of the arms. Some cirri measure as much as 2 mm.in length. In 
two of the specimens the surface between the large cirri is almost 
smooth, in others it is very rugose. All have the ventral surface 
smooth. Colour dull lilac, heavily marked on the dorsal surface 
with minute purple-black chromatophores. The specimen M **** 
was compared with the type in the Paris Museum and appeared 
to resemble it very closely. 
The latter was carefully set up in such a manner that a good 
comparison could be made. The Indian Museum specimens are, 
perhaps, a little more purple than the type but nevertheless the 
colouring and sculpture are very like. 
The umbrella in the type is very short and much continued 
up the arms, and the tip of the hectocotylized arm is very minute. 
Enlarged suckers are present on the second and third arms, the 
largest being just above the umbrella. 
The principal measurements of three specimens are ap- 
pended :— 
Specimen number .. M $192 M 8248 M S244 
mm. mm. mm. 
End of body to mantle-margin iI 17 22 
Heory\s CY. Gre: ; 18 Bit 22 
Eye to umbrella _... Ace 12 22 24 
Breadth of body _... “ts 14 i 24 
teal o(ere ya os Be IO iit 20 
