88 



slender. Eyes deeply sunk in their orbits, so as to be scarcely 

 visible from above. Chelipeds, large and unequal. The inner 

 edge of the carpus is smooth and unbroken. The fingers touch 

 only at their tips and are slightly twisted. The wrinkles on the 

 carapace are more conspicuous in the females than in the males. 



Size. — Large specimens are sometimes 10 mm., from front to 

 back of carapace, but the average measurement is about 6-8 mm. 



General Distribution. — The species extends from the south- 

 west of Norway, along the coasts of western Europe into the 

 Mediterranean and the Black Sea. South-west of Norway 

 (G. O. Sars, Appellof), Skagerrak and Kattegat (Meinert, 

 Bjorck), Sweden (Gees), Heligoland (Ortmann), British coasts 

 (Bell), Bay of Biscay (Milne-Edwards), Spanish and Portuguese 

 coasts (Heller), Canaries (Heller), Mediterranean and Adriatic 

 (Heller, Cams), Black Sea (Heller). 



Irish Distribution. — Very common all round the coast. 



Vertical Distribution. — From between tide-marks down to 

 about 20 fms. 



Tribe THALLASSINmEA. 



The families containing Irish species may be separated as 

 follows : — 



A. — No linea thallassinica ; abdominal pleura 



large, . . . . . . . . . . Axiidae. 



B. — Linea thallassinica present ; abdominal pleura 

 usually small : — 



1. Both endopodite and exopodite of 



uropods with transverse suture ; 

 podobranchs on at least first three 

 pairs of pereiopods, . . . . Laomediidae, 



2. Neither endopodite nor exopodite of 



uropods with transverse suture ; 

 pereiopods without podobranchs, 



C ALLIANASSID AE . 



Family AXIIDAE. 



The family contains four genera Axius, Axiopsis, CalocariSy 

 and Scytoleptus, but we are concerned here with only two of 

 these, Axius and Calocaris, which may be separated by the 

 following characters : — i 



Body compressed ; no median dorsal ridge 

 on carapace ; no suture on the^exopodite of 

 the uropods, . . . . . . . . . . Axius. 



Body almost cylindrical ; a median dorsal 

 ridge on the carapace ; a suture on the exopo- 

 dite of the uropods, . . . . . . Calocaris, 



