354 DISCOVERY REPORTS 



(3) Dr Wheeler has been kind enough to give me specimens from Bermuda of two 

 distinct forms, one of which differs strikingly from all the others I have seen in having 

 the propod of leg 4 expanded as well as that of leg 5. 



(4) The Discovery material which has been entrusted to me by Dr Kemp contains a 

 few specimens of Eretmocaris larvae which are separable into five types, two of which 

 have already been described by Bate. 



LARVAE FROM THE RED SEA 



Larvae of the Eretmocaris type were taken in very small numbers in plankton from the 

 deeper water outside the reef at Ghardaqa, and occasional specimens of stage I appeared 

 at night near the laboratory. Two forms can be distinguished, the most obvious distin- 

 guishing character being the presence or absence of dorsal spines on abdominal somite 5 ; 

 but there can be little doubt that the specimens referred to as "species 2" actually 

 represent two species, since some specimens have supra-orbital spines while others 

 have not. Apart from this difference the larvae, having regard to the scantiness of the 

 material, cannot be separated. 



Species R.S. I, Hippolysmata? 



Stage I. Length 2-3 mm. (Figs. 1-7). 



Rostrum long and slender, reaching end of antennular peduncle. Carapace with 

 anterior and posterior median dorsal tubercles ; anterior ventral margin with four teeth. 

 Abdominal somite 5 with a pair of small dorso-lateral teeth. Telson deeply concave 

 behind. 



Antennule. Exopod with inner feathered seta and four aesthetes ; of these the inner 

 one is short and stout, but bears at its end a spoon-shaped membrane with thickened 

 midrib and distal margin (Fig. 3). It seems to be a general rule in Caridea that there is 

 a feathered seta and four aesthetes, one of which differs from the others in most cases 

 by tapering to a fine point. In Saron and a species allied to it I have detected a very 

 delicate membrane on either side of it, but narrower and much more difficult to see than 

 in Lysmata. 



Antennal scale with four distinct segments; two outer setae and eleven inner and 

 terminal ; endopod a slender rod bearing a long feathered seta. 



Maxillule. Palp unsegmented, with five setae. Maxilla, exopod with five setae; 

 endopod with three small inner lobes bearing setae, unsegmented; four inner laciniae 

 distinct. 



Maxillipede i. Endopod of four segments; exopod with three terminal setae, and one 

 on outer margin ; coxa large, with long setae. Maxillipedes 2 and 3 with long exopods 

 bearing three terminal and six lateral setae. One very small leg rudiment. 



Chromatophores of legs, mouth region and telson dark olive brown; dark red in 

 thorax between maxillipedes, and rosy red in antennules. 



