278 A HISTORY OF EECENT CRUSTACEA 



Haplosti/las, Kossraann, was established to receive tbe 

 Mediterranean species, Gastrosaccus Normani, Sars, wbicii 

 is also found off tbe coast of Ireland, and a Red Sea species, 

 HapLostylus erythrceus^ Kossmann, tbe generic distinction 

 consisting in the absence of tbe forward directed lobes on 

 tbe concave binder rim of tbe carapace, wbicb are found in 

 tbe species of Gastrosaccus above mentioned, and also in 

 tbe reduction to a rudiment of tbe inner natatory brancb 

 of tbe tbird pleopods of tbe male. 



It will be Feen from tbe foregoing notes tbat fifteen 

 genera of tbis family are represented in tbe Fauna of Great 

 Britain, and it is quite possible, and even probable, tbat 

 extended research may sbow tbat others of the genera 

 and species occur round tbe very varied coasts of tbe 

 British Isles, which in their "southern parts, especially if 

 the Channel Islands are included, are in rather marked 

 contrast to the region of the Orkneys and tbe Shetland 

 Isles, among wbicb Norwegian and Arctic forms may 

 readily present themselves. It will be understood that, 

 although an endeavour has been made to mention all the 

 valid, or at least all tbe commonly accepted, genera of the 

 Schizopoda, there are very numerous species belonging to 

 those genera of which it has been impossible to take 

 notice. 



