56 

 I. '21. 



rate at the base, are composed of two joints, and are 

 pressed against the last thoracic sternum. The unpaired 

 pleopods are four in number, the three anterior ones alone 

 serving for the attachment of the ova as usual. The 

 inner or posterior branch remains free ; it is broader and 

 and much shorter than the anterior branch. Both sex- 

 ual openings are present in the female." 



Size. — The length of the carapace in the single. Irish specimen 

 is 7'5 mm. 



General Distribution. — The species has been recorded by 

 Milne-Edwards and Bouvier from the north coast of Spain, 

 the Atlantic coasts of Spain and Portugal, near Toulon, the 

 west coast of Morocco and the Sudan down to the Cape Verde 

 Is. and the Azores. The specimen taken by the Helga off the 

 west of Ireland extends the known distribution of the species 

 nearly ten degrees to the north. 



Vertical Distribution. — The depths at which the species has 

 been taken range from 57 to 438 fms. 



Irish Distribiition. — The Helga has taken only a single speci- 

 men, the first to be found in British waters. 



Helga. — 



S. R. 178. —16 XI '04.— 40 mis. N.W. by W. | W. of Cleggan 

 Head, 53° 36' 30" N., 11° 15' 30" W., 74| fms., 

 coarse gravel and stones. Dredge. Temperature 

 10-8° C— One, 7*5 mm. 



Family LITHODIDAE. 



Genus Lithodes, Latreille 



Lithodes maia (Linn.) 



Plate IX, figs. 1-4. 



Lithodes Maia, Bell, 1853. 

 Lithodes arctica, Bouvier, 1895. 

 Lithodes Maja, Bouvier, 1896 (a). 

 Lithodes maia, Lagerberg, 1908. 

 Lithodes Maja, Hansen, 1908. 

 Lithodes Maja, Stephensen, 1913, 



In general aspect this species is crab-like. It does not live 

 m a shell like the species of Paguridae described above, though 

 the structure of the abdomen and pleopods in the female clearly 

 indicate that it has been evolved from similar asymmetrical 

 stock. 



The carapace is pear-shaped or obcordate. The rostrum is 

 produced into a long process ending in a bifid point and bearing 

 a number of other spines. On the upper surface, near the middle, 

 there is a pair of large spines, projecting upwards and forwards, 



