CRUSTACEA FROM THE FALKLAND ISLANDS. 367 



body is mneli less conspicuously dentate than in any other 

 described species of the genus, having a medio-dorsal tooth 

 extended backwards only on the second, third, and fourth pleon 

 segments, this tooth being flanked on the third segment by a 

 very small pair of additional teeth, which may be present also on 

 the second segment but were not perceived. The mouth-organs, 

 both gnathopods, uropods, and telson, are in close agreement 

 Avith those described and figured by Chevreux tor P. Jissicauda, 

 15 mm. in length. In the first maxillae, howevei-, there is oidy 

 one seta on the narrowly oval inner plate, and few setfe on the 

 single-jointed palp. The inner margin of the inner plate of the 

 second maxillai! could not be made out. The fifth joint in the 

 first gnathopods is not longer than the sixth, but in the other 

 species the difference in length appears to be very slight. In the 

 fourth peraeopods the second joint has a convex hind margin, not 

 a sinuous one as in the species compared. The telson does not 

 reach the end of the third uropods, and each of its long narrow 

 lobes has three or four spines along its outer margin with two 

 unequal spinules at the apex. The flagellum of the first antennse 

 is composed of fourteen joints, that of the second is more slender 

 with nine joints ; in both pairs the joints in general being con- 

 siderably longer than broad. Each of the two specimens mea- 

 sured 2-5 mm. The one dissected contained numerous eggs, and, 

 whatever allowance is made for variability, I think it would be 

 scarcely reasonable to regard this matron, a tenth of an inch long, 

 as belonging to the same species as a congener over thirty times 

 her bulk. 



Locality. Stanley Harbour, in seaweed at low water of spxing 

 tide. 



Fam. TalitriDjE. 

 1906. Talitridce Stebbing, Das Tierreich, vol. xxi. pp. 8, 523, 735. 

 1913. „ G. M. Tiiomson, Tr. N. Zealand Inst, vol xlv" 



p. 243. 

 Thomson is " inclined to reduce Talitrus, Talitroides, Orches- 

 toidea, Talorchestia, and Parorchestia to Orchestia" But to play 

 the part of Saturn swallowing his children, he should have chosen 

 Talitrus in preference to Orchestia. Caiman in 1912 agrees with 

 him in questioning the independence of Talitroides. 



Gen. Talorchestia Dana. 

 1852. Talorchestia Dana, Amer. J. Sci. ser. 2, vol. xiv. p. 310. 



1906. „ Stebbing, Das Tierreich, vol. xxi. p. 543. 



1907. ,, Chevreux, Mem. Soc. Zool. France, vol. xx 



p. 495. 



Talorchestia scutigerulus (Dana). 



1853-5. Orchestia scutUjerula Dana, U.S. Expl. Exp. vol. xiii. 



p. 863, pi. 58. fig. 2. 

 1862. „ „ Bate, Catal. Amph. Brit. Miis. 



p. 26, pi. 4. fig. 7. 



[27] 



