OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 269 



The colouring might easily suggest such names as the violet or purple crab, which 

 have been applied to G. ruricola, and shows correspondence with the figure which 

 Guerin gives of G. lateralis. Miers says of the small specimen from Bermuda 

 which he identifies with G. lagostoma, that in colour it nearly resembles specimens 

 of G. lateralis, a species to which Heilprin and Ortmann definitely assign it, only 

 with the difference that Ortmann regards G. lateralis as merely a young form of G. 

 ruricola. The latter opinion is not accepted by Miss Rathbun, and does not appear 

 to be tenable, if reliance can be placed on the number of spine-rows in the ambulatory 

 fingers as having specific value. These rows are six in number in the small as well 

 as in the large specimens of G. lagostoma. But in a specimen from Antigua, sent 

 me by G. R. Forrest, Esq., which measures 58 mm. in breadth by a length of 45 mm., 

 these rows are limited to four. The specimen has a very large left cheliped, with 

 gaping fingers, and by the pleon and appendages is clearly an adult male. A third 

 pair of carinse on the ambulatory fingers is at least indicated, though it is not spini- 

 ferous. Also the fourth joint of the third maxillipeds has a fissure, though less in 

 extent than that in G. lagostoma. On the whole, it is perhaps not surprising that 

 authorities have varied in applying the names ruricola, lateralis, and lagostoma 

 with others which are noted by Miers, Ortmann, and Rathbun. 



The male specimen obtained by the Scotia has the pleon appendages wide apart, 

 about reaching the end of the sixth segment, with a short subapical fringe directed 

 outward. Breadth of carapace 43 mm., length 34 mm. 



Locality. — Ascension Island, 5 to 18 fathoms; Station 507. 



Family Hymenosomatid^e. 



1858. Hymenosomidx, Stimpson, Pr. Ac. Sci. Philad., vol. x. p. 108. 



1905. Hymenosomatidx, Stebbing, Gilchrist's Mar. Invest., "S.A. Crust.," part iii. p. 49. 



1906. Hymenosomidx, W. H. Baker, TV. R.S. South Australia, vol. xxx. p. 112. 

 1910. Hymenosomatidae, Stebbing, Ann. S. Afr. Mus., vol. vi. part iv. p. 331. 



As genera belonging to this family there have been named Hymenosoma, 

 Desmarest, 1825; Elamena, Milne-Edwards, 1837; Halicarcinus, White, 1846; 

 Hymenicus, Dana, 1852. The specific names which have been distributed among 

 these genera need to be revised by someone who can compare specimens from the 

 several localities concerned. 



Genus Hymenosoma, Desmarest. 



1825. Hymenosoma, Desmarest, Consid. gen. Crust., pp. xvii, 163. 



1900. „ Stebbing, Pr. Zool. Soc. London, pp. 520, 523. 



1905. ,, Stebbing, Gilchrist's Mar. Invest., "S.A. Crust.," part iii. p. 49. 



1907. ,, Stimpson, Smithson. Misc. Coll., vol. xlix. p. 144. 



1910. ,, Stebbing, Ann. S. Afr. Mus., vol. vi. part iv. p. 331. 



In 1900 I was inclined to agree with Professor Haswell's opinion that the 

 separation of Halicarcinus from Hymenosoma rested " on extremely slight points of 

 TRANS. ROY. SOC. EDIN., VOL. L. PART II. (NO. 9). 38 



