19106. | S. Kemp: Notes on Crustacea Decapoda. 389 
The peraeopods closely resemble those of T. faschalis. The car- 
pus of the second pair (text-fig. Id) is composed of six sub-segments 
the proportional lengths of which are much the same as in T. pas- 
chalis, except that the third is comparatively a little shorter. 
There is practically no difference between males and females in 
the length of the third pair of legs (text-fig. re). On the lower 
border of the merus of the third and fourth pairs there is a small 
subterminal spine. This spine is present on all the last three pairs 
in T. paschalis,| whereas in T. discosomatis it is absent from the 
last pair. 
On the telson (text-fig. Ig) as in T. paschalis there are three 
or four pairs of dorso-lateral spinules. At the apex, however, 
there are four pairs of spines, the outermost the shortest, the 
second the longest and the two inner pairs sub-equal (text-fig. 1/2). 
In T. faschalis there are only three pairs of terminal spines. 
In the shape of the antennal scale (text-fig. 1b) and in all 
other features, IT. discosomatis seems to bear the closest resem- 
blance to T. paschalts. 
The largest specimen obtained, an ovigerous female, is 13 mm. 
in length. 
The colouration of living specimens was very remarkable, the 
animal being of a deep reddish brown tint, semitransparent, with 
very large spots and patches of pale greenish yellow. On the 
carapace are two such spots, round and confluent in the mid- 
dorsal line; there is one on either.side of the second abdominal 
somite, a broad transverse band on the fourth somite with a small 
spot on each side below it, a ventral transverse bar on the fifth 
somite and a patch, forming a complete ring, on the sixth somite. 
Each of these spots or patches is very pale green in the centre, 
with a broad margin of bright yellow, the whole being narrowly 
circumscribed by blue. The central portions are traversed by 
streaks of yellow extending inwards from the margin. ‘The apex 
of the telson is greenish yellow and there is a circumscribed spot 
in the middle of each uropod. On the upper side of the eyestalk 
there is a greenish yellow patch; all the other appendages are 
reddish brown. 
The specimens of Thor discosomatis were found along with a 
Palaemonid in the immediate vicinity of large anemones of the 
genus Discosoma. ‘Two very small individuals were obtained in 
the dredge, but it is probable that on this occasion the net was 
drawn over an anemone in the course of its passage along the 
bottom. 
The Palaemonid has been described by Nobili under the name 
Ancylocaris aberrans,* and of this species Miss Rathbun’s Periclt- 
menes hermitensis* is apparently a synonym. Coutiére,# who 
| These spines are omitted in the figure given in pl. i, fig. 6, op. cit., 1914. 
* Nobili, Bull. sci. France Belgique, XL, p. 52, pl. iv, tigs. 9-9) (1906). 
> Rathbun, Proc. Zool. Soc. London, 1914, p. 655, pl. i, figs. 1-3. 
4 Coutiére, Bull. Mus. d’ Hist. nat., Paris, \V, p. 198 (1898). 
