1900.] FEOM THB FALKLAND ISLANDS. 521 



Desinarest he quotes the Museum name of the species, " Hymeno- 

 soma Mathaei, Latreille." Like Desinarest he refers to the Ile-de- 

 E ranee as the place of origin, but adds the Red Sea, because he 

 is able to refer to Riippell. 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. Bat to those who would lay any overwhelming weight 

 on a discrepancy of that kind, it may be pointed out that Riippell, at 

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

 crustacean appears never to overstep a length (Laugendurchmesser) 

 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, page 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 Red Sea, p. 71, 1875) is right in regarding the species 

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

 name mathaei (matJiei 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. Halicaecikus "White. 



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

 p. 178. 



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



1852. Halicarcinus, 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, Reports, 

 vol. xvii. p. 280. 



White in 1846 placed this genus in the family Myctiridae, 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 



