742 DR WALTER E. COLLINGE. 



and somewhat narrow, basal plate and epipodite long, groove on the third joint of 

 the palp only small. Thoracic appendages (figs. 43 and 44) stout. Metasome 

 (fig. 46) with two short segments and lateral indications of a further coalesced one, 

 terminal segment broad, slightly convex, lateral margins curved, posterior margin 

 slightly emarginate, with truncate median portion, lateral angles projecting. 

 Uropoda (fig. 47) with almost parallel sides, posterior margin slightly emarginate, 

 endopodite with straight internal lateral margin, externally sloping, posterior 

 margin emarginate. 



Length of <? 30 mm., of ? 20 mm. 



Colour variable. 



Geographical Distribution. — Common all round our coasts. I have records from 

 numerous localities, amongst which may be mentioned the following : — Wick, Caith- 

 ness, Moray Firth, Aberdeen, St Andrews Bay, Firth of Forth, Northumberland 

 and whole of the eastern coast, Sussex, Dorset, and Devon coasts, Welsh coast, 

 Firth of Clyde, Firth of Lorn, Skye and Sutherland coast. Also recorded from 

 Kattegat (Meinert) and coasts of France and Spain. I have what 1 believe to be 

 young examples of this species from the Mediterranean. 



Remarks. — This species stands out as distinct from any other member of the 

 genus, its large size and robust form contrasting strongly with any other species, 

 excepting /. baltica, from which it differs, however, in quite a number of struc- 

 tural details. 



Some small, dark-coloured male forms which have been examined, at first sight 

 bear a superficial resemblance to /. metallica, but in nearly all cases they have a 

 slight median stripe running down the middle of the mesosomatic segments, which 

 at once serves to distinguish them, as also the more convex mesosome, and in being 

 wider anteriorly than posteriorly. 



Like /. baltica (Pallas) this species is subject to great variation in its colour 

 markings. 



(5) Idotea granulosa, Rathke. (PL V, figs. 48-58.) 



Idotea granulosa, Ratbke, Beitrdge zur Fauna Norwegens, 1843, p. 23. 



Idotea phosphorea, Harger, Rep. U.S. Comms. Fish and Fisheries, 1874, part i, p. 569 ; Proc. U.S. Nat. 



Mus., 1879, vol. ii, p. 160; Rep. U.S. Comms. Fish and Fisheries, 1880, part vi, p. 347, pi. v, 



figs. 27-29. 

 Idotea marina, war. phosphorea, Miers, Journ. Linn. Soc. Lond., 1881, vol. xvi, p. 31. 

 Idothea granulosa, G. 0. Sars, Crust. Norw., 1897, vol. ii. p. 82, pi. xxxiv, fig. 1. 

 Idotea granulosa, Norman, Ann. and Mag. Nat. Hist., 1904 (s. 7), vol. xiv, p. 441; Tattersall, Nord. 



Plank., 1911, p. 223, tigs. 94-99. 

 Idothea phosphorea, Richardson, Bull. No. 54, U.S. Nat. Mus., 1905, p. 367, 3 figs. 



Body oblong oval, moderately convex, dorsal surface finely granular or almost 

 smooth. Cephalon (fig. 48) broader than long, with the anterior margin almost 

 straight, posteriorly with transverse sinuous line. Eyes moderately large, situated 

 just in front of the median transverse line on the lateral margin. Antennulse 



