CRTTSTACEA. 293 



above the scale of the external antennoe, which is armed with a 

 spinule at its antero-external angle. This I propose to designate 

 H. sjpinuUferus. 



13. AncMstia petitthouarsi, Audouin ? 



The carapace, with its rostrum, is shaped nearly as in Palcemon ; 

 the terminal postabdominal segment is narrow, with four spines on 

 its upper surface, placed close to the lateral margins, and terminates 

 in two long mobile spines and three smaller spines. There is a 

 supraorbital spinule situated on each side of the rostrum, between 

 it and the eyes and just behind the anterior margin of the carapace, 

 also an antennal spine outside of the eyes, and one (the branchio- 

 stegal?) placed below the eyes and behind the anterior margin. 

 The rostrum is longfer than the peduncles of the antennae, nearly 

 straight, has six teeth on its upper and four on its lower margin, 

 and is bidentate at apex ; the last tooth of the series is situated in 

 the median dorsal line of the carapace behind the anterior margin. 

 The eyes are, as in Leander, oi moderate size and project laterally. 

 The antennules have the antepenultimate (?) joint of the peduncles 

 dilated, laminate, and vertically compressed, with a small spinule 

 at its antero-external angle ; the two following joints are short and 

 slender and terminate in two flagella, of which the thicker is shortly 

 bifid at its apex, the other is broken. The antennal scale is much 

 elongated, narrow, nearly reaching to the apex of the thicker an- 

 tennulary flagellum, and completely concealing (in a dorsal view) 

 the peduncles of the antennae ; it is ciliated on its inner margin and 

 at its apex, and has a spinule at its antero-internal angle ; the an- 

 tennal flagellum is about as' long as the animal. The outer maxil- 

 lipedes are subpediform, with the antepenultimate but little thicker 

 than the last two joints, the penultimate longer than the last joint. 

 The anterior legs (or chelipedes) are very slender, with the wrist as 

 long as the palm and fingers together ; the second legs are slender, 

 but thicker than the preceding ; merus-joint with a small spine at 

 the distal end of its inferior margin ; the wrist, which is little 

 longer than the palm, is also armed with a spine at its distal ex^ 

 tremity ; the palm is very slender, nearly terete, and about as long 

 as the fingers ; these latter are without teeth on the inner margins, 

 and have the tips slightly incurved. The ambulatory legs are 

 slender and clothed with a few distant hairs ; the penultimate 

 joints very long ; the dactyli slender, styliform, nearly straight, and 

 not half as long as the preceding joints. The bases of the uropoda 

 have a small spinule at the distal end of the outer margin, and there 

 are two subterminal spinules on the outer margin of each outer 

 ramus ; the rami are subovate (as usual) and ciliated at the distal 

 extremity and along the inner margins ; the outer somewhat broader 

 than the inner ramus. Colour (in spirit^ whitish. Length nearly 

 10 lines (21 millim.). 



The unique specimen (a female with ova) was obtained at Port 

 Molle on the beach (No. 98). 



