1900.] PHOM THE FALKLAND ISLANDS. 521 



Desmarest he quotes the Museum name of the species, " Hyrneno- 

 soma Mathaei, Latreille." Like Desmarest he refers to the lle-de- 

 Erance as the place of origin, but adds the Eed Sea, because he 

 is able to refer to Eiippell. It is indeed reasonable to suppose 

 that Desmarest and Milne-Edwards were describing identically 

 the same specimen. It must be admitted that Desmarest says that 

 it is 6 lines long, while in Milne-Edwards's ' Histoire ' it is 4 lines 

 in length. But to those who would lay any overwhelming weight 

 on a discrepancy of that kind, it may be pointed out 1 hat Eiippell, at 

 the outset of his description of this very species, says " This minute 

 crustacean appears never to overstep a length (Langendurchmesser) 

 of three lines," although at the close he says : " Comparisons 

 in the Paris Museum convinced me of the identity of the species 

 here described by me with that which M. Desmarest (Consider- 

 ations sur les Crustaces, ])age 163) has published under the same 

 name," It will be remembered that Desmarest gives the length 

 not as three lines but as six. It seems clear that Paulson (Crus- 

 tacea of the Eed Sea, p. 71, 1875) is right in regarding the species 

 described by Desmarest, Eiippell, and Milne-Edwards under the 

 name mathaei (mathei Eiippell) as one and the same. 



Nevertheless, Professor Haswell's suggestion is likely enough to 

 be right with regard to the second account given by Milne- 

 Edwards, in 1853, when he changes Elamena into Elamene, figures 

 parts of a male specimen, which on the earlier occasion he had 

 confessedly not had an opportunity of examining, and introduces 

 into the generic character a tridentate rostrum which is conspicuous 

 by its absence in the figure of his Elamene quoyi. 



Gen. Halicabcinus White. 



1846. Halicarcinus, White, Ann. Mag. Nat. Hist. ser. 1, vol xviii. 

 p. 178. 



1849. Liriopea, Nicolet, Gay's Hist. Chile, Zool. vol. iii. p. 158. 



1852. Halicarcimis, Dana, U.S. Expl. Exp. vol. xiii Crust 

 pt. i. p. 379. 



1853. Halicarcinus, Milne-Edwards, Ann. Sci. Nat. ser. 3 

 vol. XX. p. 222. 



1876. Halicarcinus, Miers, Catal. Crust. New Zealand, p. 49. 



1877. Halicarcinus, Targioni-Tozzetti, Crost. della Magenta 

 p. 172. 



1882. Hymenosoma (part), Haswell, Catal. Australian Malaco- 

 straca, p. 114. 



1886. Halicarcinus, Miers, 'Challenger' Brachyura, Eenorts 



vol. xvii. p. 280. .' ' F . 



White in 1846 placed this genus in the family Myctirida, as a 

 subgenus distinguished from Hymenosoma " by the great size of the 

 thickened fore -feet, by the carapace being generally wider than 

 long, and having the edge of the strongly depressed upper surface 

 with two teeth or angles on each side. The four last pairs of legs 

 are cylindrical and free from hairs, while the claws are considerably 



[5] 



