CARCiNOLOGICAL STUDIES. 31 



12, Gelasimus coarctatus M. E. 



(PI. 3, fig. 8). 



Gelasimus coarctatus, H. Milne Edwards, 1. c. p. 146, PI. III, 

 fig. 6. — A. Milne Edwards, in: Nouv. Archives du Muséum, T. 

 IX, p. 272, PI. XII, flg. 4. 



Gelasimus forcipatus , Kingsley, 1. c. p. 142, PI. IX, fig. 9. 



A fine male from the Moluccas , collected by Macklot , 

 and a young male from the Island of Ponape. 



This species is closely allied to Gelas. Dussumieri and 

 Gelas. Urvillei, but differs by the following characters. 



The cephalothorax resembles much that of Gelas. Dus- 

 sumieri, it being about quite as long in proportion to 

 the distance between the external orbital angles , but the 

 lateral margins are (at least in our two specimens) straight 

 or even slightly concave and still more oblique. The 

 narrow frontal furrow presents the same form in both 

 species. The wall of the orbits is ornamented with au 

 accessory row of granules near the inferior margin; 

 the row consists only of four or five rather prominent 

 granules. 



The larger hand of the male closely resembles that of 

 Gelas. Dussumieri, but it may always be distinguished by 

 the existence of a prominent tooth near the ex- 

 tremity of the upper or mobile finger; this tooth 

 is constantly wanting both in Gelas. Dussumieri and in 

 Gelas. Urvillei. In the young male from Ponape this distal 

 tooth is already present. Both fingers are longitudinally 

 furrowed on their outer surface. 



Measurements: (ƒ cT 



Distance between the ext. orb. angles 26'/4 mm. 15'/^ mm. 

 Length of the cephalothorax . . 15 » 9*^/3 » 



I think Kingsley is wrong when uniting Gelas. forcipatus 

 White with this species , because in the former also the 

 lower finger of the larger hand of the male seems to be 



Notes from, the Leyden IMuseuixi , Vol. !X.I1I. 



