23 



very small. Incubatory lamella- likewise small, lanceolate, with only few marginal 

 setae. Telson rather broad, rounded at the tip. 



Remark*. The present genus is ehietly dislin.n-iiisli.-d from ()>-flirxt'ni 

 liy the anterior gnathopoda being simple, not subclieliform, and the posterior 

 ones being exactly alike in the two sexes; moreover Ity tin- less compressed 

 form of the body. It comprises only a tew species, llie validitv of \vhich 

 would moreover seem to be rathe]- doubtful. 



1. Talitrus locusta (Pallas). 



(Tl. 9). 



i? locnxta, Pallas, Spocil. Zool. fase. 9, tab. -1, !!-. 7. 

 Syn : Tdlitrits srtltntor (Mont.), Kd'.v. 



liody comparatively short and robust, with the cnxal plates scarcely 

 as deep as the mesosome, 1st pair triangular, more or less covered bv 1lie -Jnd ; 

 5th pair nearly as deep as the preceding ones. (Vphahm rather deep. irans- 

 versely truncated in front, with the buccal mass greatlv projecting. K 

 comparatively small, rounded, with black pigment. Superior antennae scarcely 

 reaching beyond the penultimate joint of the peduncle of the inferior, lla^'ellum 

 much shorter than the peduncle, 7 8-articulate. Inferior antennae in female 

 about three times the length of the superior, with tin* last joint of the peduncle 

 as long as the two preceding ones combined, nagellnni about the length of llie 

 peduncle; in male much stronger, sometimes nearly as long as the whole body. 

 Anterior gnathopoda with the propodal joint scarcely more than halt' llie lenn'tli 

 of the carpal and slightly tapering distally. Pleopoda with the basal part about 

 the length of the rami and beset on the outer edge with slender spines. La-t 

 pair of uropoda with the ranius nearly as long as the basal ]art and bearing a 

 single slender spine at the tip and several short ones on the outer edge. Telsmi 

 nearly twice as broad as it is long, with bunches of small spines dorsally. 

 Colour, when alive, light greyish white, with dark bluish markings on t In- 

 back. Usual length of adult male 1(> mm; that of female soinewliat les.- 



Eetmtrl-x. Although the description and tiguiv given by Pallas of 



his Oiuscit* locuxta is very imperfect, there is all reason to believe, llial he 

 has had this form before himself and according to lln- rules of priority liis 

 .specific name htnvffi ought therefore to be preferred to thai of saltator proposed 



by Montagu. 



Ocrnrmtr<: I have met with this form rather plenty fully on tin- 



sandy beaches of Lister, on the south coast of Norway, where it occurred 

 near the level of spring tide liighwatcr mark, beneath old sea weed. 



