106 MR. OWEN’S DESCRIPTIONS OF 
the dark red colour of which had changed in the spirit to a dingy brown; these spots 
occur also, but of more minute size, on the fins, and on the exterior of the arms and 
tentacles. A narrow line extends down the middle of the back of the mantle, through 
the whole length ; this line, when viewed by transmitted light, is transparent, the pa- 
rietes of the mantle being at that part extremely thin, and containing a colourless pel- 
lucid style of gelatinous consistency, pointed at both extremities, but of almost uni- 
form breadth through the whole length, being very slightly contracted in the middle. 
The diameter of this representative of the gladius is;;th of an inch ; its length is equal 
to that of the mantle. 
The surface of the mantle, from which the trivial name of the present species is de- 
rived, next claimed attention ; on viewing this part under the microscope, it was seen to 
give off innumerable small flattened processes, varying from a thirtieth to a fiftieth of 
an inch in breadth, and about a fiftieth of an inch in length, and terminating in two, 
three, or four sharp-pointed processes ; these give to the outline of the mantle, under the 
microscope, an irregularly denticulated appearance. The surface of the skin, though ge- 
nerally smooth, presents several remarkable irregularities in other species of Cephalopods; 
thus it is beset with branched papille in the Sepia papillata, with more simple obtuse 
eminences in Sepia mammillata, with tubercles in Sepia tuberculata, with sharp-pointed 
tubercles in Octopus aculeatus, &c., to which the aculeated lamelle of our subject make 
a near approach ; it is highly probable that these different cutaneous processes serve to 
indicate to the Cephalopods possessing them the nature of the surfaces with which they 
may come in contact, and augment their sense of touch. 
The terminal fins, which appear to have been lacerated in Cranch’s specimen, were 
entire in ours ; they are of a regularly rounded form, approximated on the dorsal aspect, 
and united at their bases, the united part extending about a line beyond the end of the 
mantle ; they are not supported by cartilages, as in Loligo, but appear to be mere redu- 
plications of the integument. 
The head is principally composed of the large lateral prominent eyes ; the circum- 
ference of the cornea is marked with a circle of closely approximated large dark spots. 
The arms have the usual conical form; the first or dorsal pair is the shortest, as in 
most Decapods ; the second and fourth nearly equal, and rather longer than the first ; 
the third pair is double the length of the first. 
The first, second, and third pair of arms are united at their bases by an intervening 
web of greater proportional extent than is usually met with in the Decapodous Cepha- 
lopods, and which is entirely wanting in the Loligines. In the Cranchia Bonelliana a 
similar web extends between the corresponding arms for full two thirds of their extent. 
Between the third and fourth pair of arms there is no connecting web, the interspace 
being occupied by the thick round stems of the elongated peduncles. All the arms are 
connected together by the external membranous lip, which gives off eight pointed pro- 
cesses ; but these, instead of projecting freely, as in most of the Loligines, the Sepioteu- 
