110 
Proceedings of the Royal Society 
The Arms are subequal, three and a half times as long as the body; 
they are slender, and more resemble thickenings of the web than 
independent arms ; they are thickest about two-thirds the distance 
along them, and terminate in a delicate slender tip, which projects 
beyond the web. The umbrella is a thin delicate membrane, very 
largely developed, and when fully expanded its diameter was probably 
nearly three times as large as its depth. It extends from the tip of 
the ventral arm on either side backwards, and becomes gradually 
narrower, so that it only extends along the proximal two-thirds of the 
next arm, and passes beneath it to be attached in a crescentic line to 
the outer surface of the web, which similarly passes backwards from 
the tip of this arm ; this arrangement is usually described by saying 
that the arm does not lie in the umbrella for the proximal two-thirds 
of its length, but is joined to it by a vertical web, but this 
does not so correctly represent the disposition of the parts. The 
umbrella stretches across from tip to tip of the two dorsal arms, 
between the proximal two-thirds of the two ventral arms. 
The suckers commence about 1 cm. from the oral margins, and 
the first four lie pretty close together within a space of less than 
2 cm., after which they gradually become further apart, an interval 
of 2-3 cm. intervening between each two ; about two- thirds along 
the arm they stand closer together, and are very large, but after 
this they again become smaller, and stand in close contiguity with 
each other. The proximal suckers are small, prominent, and rather 
soft, and seem to contract by folding the lateral margins over 
towards each other, so as to present the appearance of a half-closed 
eyelid ; but the largest suckers are firm and muscular, and consist 
of a globular basal portion imbedded in the arm and a short 
cylindrical projecting portion. The cirri commence between the 
fourth and fifth suckers as very minute prominences, which 
gradually increase in length until halfway along the arm they 
attain a maximum length of 8 cm., after which they decrease 
rapidly, and cease opposite the attachment of the web to the ventral 
aspect of the arm. 
The Surface of the body has been entirely denuded of epidermis, 
so that it is impossible to ascertain its nature ; the web is perfectly 
smooth. 
The Colour, so far as preserved, is a dull madder. 
