Report on the Crustacea ScJrizopoJa of Ireland. 239 



Distribution. — Falmouth ; Plymouth ; Sealiam ; N. Wales ; E. and W. Scot- 

 land (A. M. N.*). 



Norwa}^ ; Sweden ; Denmark ; Naples ; Black Sea (A. M. N.*). 



Genus Macropsis, Gr. 0. Sars. (See Note added in Press, p. 250.) 



Genus Macromysis, A. Wliitc. 



Macromysis flexuosa (Miiller). 



Not in the Survey Collection. 



Marine Laboratory. — Aran; Blacksod Bay ; Ballynakill ; Inisbofin ; 1899. 



Museum, Dublin. — No. 85, 1893, Bantry Bay, per A. Ti. C. Newburgh. 



No. 122, 1892, Bantry Bay. 



No. 122, 1892, Dunbeacon Harbour, Bantry Bay. 



No. 122, 1892, S.W. of Ireland. 



Unregistered. Dunbeacon Harbour; Broadhaven, 1873; Merrion, Co. Dublin, 

 per G. Y. Dixon. 



Previous Irish Records. — "All our coasts" (A. M. N.*). 



Distribution. — British coasts. 



Atlantic coasts of the European continent; Baltic; Black Sea (?), (A.M.N.*). 



Of all British M3^sidiB with which wo are acquainted, the genus Macromysis 

 appears to present the greatest difficulty in the determination of the species, on 

 account of the unsatisfactory nature of the characters by wliich 31. flexuosa and 31. 

 neglecta have been separated by Sars and Norman. Were it not for the high 

 authority of these observers, we might be inclined, witli little ceremony, to relegate 

 one species to the synonomy of the other, a proceeding hardly justified by our 

 experience of the family. We must, however, admit that we have never seen a 

 really typical specimen of 31. neglecta as redefined by Norman. The distinctive 

 characters of the two may be summarised (from Norman) as follows : — 



31. neglecta. 31. flexuosa. 



Antennal scale. — Ca. 5 times as long as 7 to 8 times as long as broad ; more 

 broad ; not twice the length of than twice the length of 2;)eduncle 

 peduncle of antennule ; ajoex of antennule ; apex scarcely ex- 

 extending twice tlie length of tending beyond spine, 

 spine of external margin. 



Tarsus. — 5-articulate, lasti-articulate. C-articulate, last 5-articulate. 



Telson.—QMi -l- of total length, very Cleft ^ of total length, moderately 



narrow and constricted at base; open; 21 to 27 lateral spines. 



18 to 20 lateral spines. 



Length. — 20 mm. 25 mm. 



2L2 



