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•Classification of the Species. 



As the result of his important researches Coutiere has proposed the very natural division 

 of the genus Alpheiis Fabr. into five groups : Megacheles , Macrochirus^ Crinihis, Brevirostris and 

 Edwardsi, the third of which is again subdivided into three subgroups : Obeso-inamis, CriniUis s. s. 

 and Insig7tis (H. Coutiere, Les Alpheidae, 1899, p. 351 and in: Alpheidae Maid, and Laccadive 

 Archipelagoes 1905). These groups are characterized by him in the following way. 



Megachcles group. 



Lateral (extra-corneal) spines present. Larger chela more or less distorted with the margins 

 grooved and notched and with the condylian crests very prominent and sharp : merus of 3"^ legs 

 dentate or unarmed, dactyli of three posterior legs simple or biunguiculate. 



Macrochirus group. 



Lateral (e.xtra-corneal) spines usually present. Inferior spine of basicerite sometimes large. 

 Larger chela usually longitudinally grooved or emarginate anteriorly. Merus of third legs 

 usually unarmed, dactyli of three posterior legs biunguiculate or simple. External spine of exopod 

 of caudal fan often black. 



Crinihis group. 



Lateral (extra-corneal) spines usually wanting. Larger chela more or less cylindrical, entire 

 or with the upper border transversely grooved or with the alpheopsial grooves well marked, 

 in the latter case the dactylus is hammer-shaped. Merus of third legs usually dentate. Dactyli 

 of three posterior legs usually simple. 



Obeso-viamis subgroup. 



Lateral (extra-corneal) spines wanting. Larger chela with the alpheopsial grooves well- 

 developed and with the dactylus hammer-shaped. Merus of third legs very rarely unarmed. 

 Dactyli of three posterior legs usually simple. 



Crinihis subgroup. 



Lateral (extra-corneal) spines wanting. Larger chela cylindrical, entire, without grooves 

 or notches. Merus of third legs very rarely unarmed. Dactyli of three posterior legs simple or 

 biunguiculate. 



Insignis subgroup. 



Lateral (extra-corneal) spines usually wanting. Larger chela with a transverse groove 

 near the articulation of the dactylus or not. Merus of third legs dentate or unarmed. Dactyli 

 of three posterior legs simple. 



17s 



