24 



PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



Fig. 4. — Synalpheus hi'ldlen- 



SIS. a, FRONTAL AND AN- 

 TENNAL RECION ; C, CARPO- 

 CERITE ; t, TELSON. 



in which the species S. latastei, of Australia and Chile, is differ- 

 entiated. I have believed it possible to separate as a distinct species 



/S. Indidensis Coiitiere from the Maldives, 

 which I have described in my work on 

 the Alpheidaj of that archipelago under 

 the name of S. tvmidomanus Paulson; 

 but S. tumidomaims is very distinct from 

 it, as shown by the angles of the telson 

 being clearly spinous (as Paulson has 

 '^~V /I /I ^U \ M \ figured it), and also by the very large 

 M J\ /I / \ \ 1\ ^^^^ which give rise to mysis. In these 



last two forms the carpocerite has be- 

 come distinctly elongate and slender (at 

 \ /^ ^^ least four times as long as wide). 



"^^ -^ I have also separated from S. pai/lso7ii, 



under the name of S. 7nnshnensis 

 Coutiere, a specimen from the Red Sea, 

 received from M. Gravier, in which the 

 antennal scale is notably shorter than the antennule and still shorter 

 than the carpocerite. This species is again extremely like S. lock- 

 ingtoni from California and Lower California. 



Although the forms with a short carpocerite are at present less 

 numerous on the Californian coast than 

 those with a long one, the parallelism be- 

 tween them and those of the Indo-Pacific 

 is again accentuated by the following 

 species which I Iwlieve should be separated 

 from S. lockingtoni. 



SYNALPHEUS PAULSONOIDES, new species. 



The species differs from S. lockingtoni 

 by the following points : 



The antennal scale equals the antennule, 

 and the lateral spine of the scaphocerite 

 considerabl}^ exceeds the carpocerite, which 

 is four times as long as wide. The carpus 

 of the small cheliped has its anterior bor- 

 der prolonged in a spinous prominence. 

 The feet of the third pair are A^ery slender. 

 Their proportions are : Carpus 1 ; propo- 

 dite 2; meropodite 2.35; this last being 

 5.3 times as long as wide. 



The specimen, a male, is unique and its large cheliped is wanting; 

 but it is very easily distinguished from S. Jorkhigtoiii, especially by 

 the slenderness of the meropodites of the third pair. It corresponds, 

 as the Inclo- Arabic S. paulsoni, to an " oxyeeros " form of the species 



Fig. 5. — Synalpheus tumi- 

 domanus. it, frontal and 

 antenxal region; c, car- 

 pocerite ; t, TELSON. 



