of the North Atlantic and of North-Western Europe. 633 



of the upper margin ; third joint triangular with six plumose setae on upper side, 

 three of which curve backwards; fourth joint with one seta above, and, at the 

 extremity below, a very large sensory organ of entirely different character from 

 that of the female, it is here a stout process, tapering to a fine extremity, very 

 closely ringed throughout, and densely beset everywhere with fine filamentary 

 threads ; fifth joint with one small seta on the face, and at its lower corner giving 

 sujjport to the terminal unguis ; last j oint with two very stout and immensely long 

 ringed setae, which are beset with lashes here and there throughout their length, 

 and three short setse. The antennae (PI. l., fig. 4) have the second joint of the 

 swimming branch equal in length to 4—5 following joints, the setae as in ? ; 

 appendicular branch larger than usual, forming a strong grasping organ, first joint 

 of equal width throughout, about four times as long as wide (PL li., fig. 12); 

 second joint as long as, but wider than the first, widening from the base to the 

 commencement of the palm, against which the unguis impinges, thence the front 

 margin slopes backwards to the extremity, and bears in the middle three short 

 setse ; unguis large, arcuate, widest in the middle, acute at the extremity, a seta 

 behind its base. The mandibular foot (PI. XLVi., fig. 13) is almost exactly as in 

 the female, the basal joint has the same falcate process, and the second joint 

 similar spear-shaped organs. 



Habitat : — " Isle of Skye" (Baird). Shetland ; Tobermory, in the Isle of Mull ; 

 off Tarbert, Loch Fyne, 20-60 fathoms ; Valentia, Ireland ; Penzance ; Plymouth ; 

 Herm (A. M. N.). Cumbrae (D. Robertson). Jersey (Sinell), north-east coast of 

 England, 25—35 fathoms (Gr. S. B.). Scilly Islands and Mulroy Lough, Co. 

 Donegal (G. S. B. and D. R.). 



Distribution. — Isle of Cherso, in the Adriatic (Grrube). SjDCzzia, Messina, 

 Groletta, and Syracuse, 5—20 fathoms (Gr. O. Sars). Bay of Biscay, at Cape 

 Breton (Marquis de Folin). Hardanger Fiord, Norway (Gr. 0. Sars).* 



* Vide TJndersogelser over Haidangerfjordens Fauna," 1871, Vidensk.-Selsk. Forliand., p. 279. This 

 tvas published subsequently to bis descriptions of A. norvegica and A. alyssicola, so that, perhaps, the 

 omission of A. marioe in the list of Ostracoda, in his recent published paper, " Oversigt af Norges 

 Crustaceen, ii. Branchiopoda, Ostracoda, Cirripedia" Vidensk.-Selsk. Forhand. Christ., 1890, p. 15. was 

 accidental. 



