ISOPOD GENUS LIGIA. 689 



I propose, therefore, on the grounds I have given above, to 

 unite Geoligia with Ligia, and regard G. simoui and G. perkinsi 

 as species of the latter genus. 



(6) Key to the genus Ligia. 



The following species are omitted from the key as being 

 insufficiently described or of doubtful validity : — L. ehrenhergii 

 Brandt, L. cajennensis Koch, L. australiensis Dana, L. cursor 

 Dana, L. vitiensis Dana, and L. malleata Pfeffer. 



The general distribution of each species is given as a possible 

 aid to identification. The key is to be considered as artificial, and 

 not necessarily indicating relationship of forms to one another. 



C Posterior margin of telson triangulate 2. 



(. Posterior margin of telson arcuate 9. 



("Process on propoclite of 1st leg of male 3. 



(.Without process on 1st leg of male 6. 



("Antennse longer than thorax in male , 4. 



(. Antenna3 shorter than thorax in male 5. 



r Telson with blunt median process and hlunt accessory processes. 

 ^ ) hawaiensis (Pacific Islands). 



■ ") Telson with acute median process and two acute accessor}' processes. 

 L exotica (warm seas). 



r Flagellar joints of antenna short and squat ... cinerascens (Japan). 



■ I Flagellar joints of antenna long and slender. 

 L occidentalis (tropical W. America). 



C With comb of long setse on carpus and merus of 1st leg of male. 

 6.-J ' 6at((^ire;ana (tropical W.America). 

 (.Without comb on 1st leg of male 7. 



r Antennae as long or longer than thorax 8. 



'1 Anteunaa not reaching further than 5th thoracic segment. 

 L pigmentata (Suez). 



First leg of male deeply grooved olfersii (tropicalE. America). 



First leg of male without grooves perJcinsi (Hawaiian Islands — 



terrestrial). 



("Width of body more than half its length 10. 



9.] 



(.Width of body less than half its length 11. 



,(■ Carpus and merus of 1st leg swollen pallasii (N.E. America). 



10.] 



(.Carpus and merus of 1st leg deeply grooved... dilatata (Cape Peninsula). 



(AnteiinEeas long or longer than whole body 12. 



11.3 



(.Antennae shorter than body 13. 



("Uropods longer than body gracilipes (S.Africa). 



12.] 



(.Uropods not so long as body natalensis (Natal). 



