1 86 The Scottish Naturalist. 



exact length. A?itennal scale. — Semi-ovate and furnished with 

 a sharp spine at the extremity of its outer margin, whose 

 inwardly bent point extends somewhat beyond the scale itself, 

 which is ciliated on its inner margin and around the point 

 to the base of the spine. Internal antenna. — Inserted directly 

 above the external antennae; first segment long and stout; 

 second, one-third the length of the first, and furnished with three 

 spines on its outer margin ; the two segments nearly reaching 

 the base of the movable portion of the external antennae ; 

 third, one-third longer than the second ; movable portion and 

 its filament broken, therefore I cannot give the length. Ex- 

 ternal pedipalps. — Two pairs, both pediform ; the internal 

 pair terminating in an obtuse, slightly knobbed tip. Feet. — 

 Simple, getting shorter from before backwards. The first pair 

 robust, with the terminal segment not multi-articulate as in the 

 succeeding pairs, the whole ciliated on their anterior margins, 

 their filaments being ciliated on their posterior margins. 

 Abdomen. — First five segments cylindrical ; the sixth compressed 

 on the dorsal edge (a transverse section would appear as a 

 triangle with the lower corners slightly rounded) ; the last 

 segment cylindrical, and somewhat swelled in the centre; the 

 first two segments lie in a sort of sternum, which is composed 

 of four pieces and within which are placed the respiratory 

 organs, composed of numerous long filaments, along which 

 are placed many minute cilia. Between the sixth and sev- 

 enth segments there is a tuft of softish spines on the dorsal 

 aspect. Tail. — Telson depressed, bifurcated, with six mov- 

 able spines on each side, and one immovable at each ex- 

 tremity. Lateral laminae lanceolate, the outer ones ciliated all 

 round, but on the outer margin the cilia become shorter and 

 stouter (might be called spines), the inner ones but half the 

 breadth of the outer, ciliated on their inner margin and for one- 

 third of the outer. The body is of a rather clear opnque white 

 throughout ; and when at rest the tail is turned under the body 

 at the junction of the fifth and sixth abdominal segments. 



Three specimens are all that have been got of this species, 

 and these were found on the sands at high water mark. 

 The first one was alive and lived a whole day without water, 

 shewing a tenacity of life much beyond what is usually observed 

 in creatures of this order. 



