1916.] S, Kemp : Notes on Crustacea Decapoda. 389 



The peraeopods closely resemble those of T. paschalis. 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. le). 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. ih). 

 In T. paschalis there are only three pairs of terminal spines. 



In the shape of the antennal scale (text-fig. 16) and in all 

 other features, T. discosomatis seems to bear the closest resem- 

 blance to T. paschalis. 



The largest specimen obtained, an ovigerous female, is 13 mm. 

 in length. 



The colouration of living specimens was ver}'- remarkable, the 

 animal being of a deep reddish brown tint, semitraasparent, 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 ver}^ 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 aherrans,^ and of this species Miss Rathbun's Pericli- 

 menes hermitensis^ is apparently a synonym. Coutiere,* who 



^ These spines are omitted in the figure given in pi. i, fig. 6, op. cit., 1914. 

 ^ Nobili, Bull. sci. France Belgiqiie, XL, p. 52, pi. iv, figs. 9-96 (igof)). 

 3 Rathbun, Proc. Zool. Soc. Loudon, 1914, p. 655, pi. i, figs. 1-3. 

 + Couticre, Bull. Mns. d'Hisf. iiat., Paris. 1\', p. 19S (1S98). 



