CRUSTACEA MALACOSTRACA. III. 201 



which have an extremely wide distribution, were known from West Greenland (O. Fabricius) and Ice- 

 land. The single genus to be mentioned here is Ligia J. C. Fabr. (this well-known name is preferred 

 and the name Ligyda Rafinesque, proposed by Richardson, discarded). 



Ligia J. C. Fabricius. 



In his "Remarks" on the Oniscoida G. O. Sars (Account, p. 153) wrote that the antennae have 

 "a 5-articulated peduncle", and this is probably generally accepted. But in Ligia oceanica I found not 

 only six joints in the peduncle, but even an exopod or squama on third joint. When the head is 

 inspected from above and somewhat from in front, and the antenna is bent downwards and turned in 

 various directions, we find (fig. 10 a) a transverse, movable piece of hard chitine (/) between the head 

 and the major outer part of next joint (2); that transverse piece is the easily seen rudiment of first 

 joint, and the remainder of the peduncle contains five joints. Furthermore a squama (ex) is observed 

 on the outer side of third joint; this squama is somewhat broader than long, with its distal half sub- 

 triangular and freely protruding, while the proximal half has a semicircular outline and is anchylosed 

 to the joint; it may be added that this suture between exopod and joint is very distinct, but in a 

 very large specimen its median part is obscure. I think the existence of six peduncular joints and 

 squama very interesting, because it shows that two such primitive features have been preserved in a 

 genus which in other organs, such as the reduced antennulse, the pleopods, and the basal joint of the 

 thoracic legs united as immovable, large epimeral plates with the segments, is very far from exhibiting 

 primary structural features. 



144. Ligia oceanica Luine. 

 (PI. XV, fig. 10 a). 



1767. Oniscus oceanicus Ljnne, Syst. Nat. Ed. XII, P. II, p. 1061. 

 1885. Ligia oceanica Budde-Luud, Crust. Isop. Terr. p. 259. 

 ! 1898. — — G. O. Sars, Account, II, p. 156; PI. 70. 



On the antennae see above. — My largest specimen, a male from Thorshavn, is larger than 

 any hitherto recorded, being 30 mm. long (without uropods) and 16-5 mm. broad. 



Occurrence. Taken by the "Ingolf" at Traugisvaag in Sudero, one of the Fceroes, in 30—40 

 feet above the level of the sea, together with Orchestia. 



It has furthermore beeu taken at Thorshavn, Stromo, at the beach by Mag. R Horring, and 

 at least three times before at the Faeroes by various collectors. Besides, it has been discovered by 

 Cand. mag. Saemundsen at the Vestmann Islands, not very far from the south coast of Iceland. 



Distribution. This species has been found on wet rocks near the surface of the sea on 

 Bornholm in the Baltic (H. J. Hansen), and at a number of places on the coasts of Denmark, at the 

 oceanic coasts of Norway northwards at least to Trondhjem (G. O. Sars), at Great Britain and Ireland, 

 at the south coast of the North Sea and at the Channel, at the Atlantic coast of France, Spain and 

 Portugal, at Gibraltar and Malaga, but is according to Roux unknown from the other coasts of the 



The Ingolf-Expedition. III. J. 20 



