lo*i rroceedinys of tlie lloyal Fhydcal Society. 



Family Sph^romid^e. 

 Genus (9) Sphaeroma, Latreille, 1802. 



12. Sphceroma rugicaitda, Leach. 



1814. Sphceroma rugicauda, Leach, Edin. Enoycl., vol. vii. p. 405. 



Habitat. — In brackish pools at Aberlady ; common. 



Genus (10) Naesa, Leach, 1818. 



13. JYoesa hidcntata (Adams). 



1798. Onisciis hidentatus, Adams, Tians. Linn. Soc. , vol. v. p. 8, 

 pi. ii. figs. 3 and 4. 



Habitat. — Found alive amongst barnacles and weed scraped 

 from a ship's hull at Granton Harbour in 1888 (cf. Ann. 

 Scot. Nat. Hist. (April 1899), p. 116). 



Valvifeka. 



Family iDOTHEiDyE. 



Genus (11) Idothea, Fabricius, 1798. 



14. Idothea baltica (Pallas). 



1774. OnisciLs balticiis, Pallas, Spieil Zool., fasc. ix. p. 66, pi. iv. 



fig. 6, A-D. 

 1825. Idotea tricusindata, Desmarest, Consid. sur Crust., p. 289. 



Habitat. — Firth of Forth, in shallow water at various 

 places (Leslie and Herdman). Moderately common upon 

 Laminaria and other sea-weeds in shallow water on both 

 sides of the estuary. 



15. Idothea pelagica, Leach. 



1815. Idothea pelagic a, Leach, Trans. Linn. Soc, vol. xi. p. 365. 

 1868. ,, ,, Bate and Westw., Brit. Sessile-eyed Crust., 



vol. ii. p. 384. 



Habitat. — " Common on the Bell Eock in the Firth of 

 Forth" (Bate and Westwood, op. cit., p. 385). "Bell Eock" 

 is doubtless, I think, a misprint for Bass Eock, for it is 

 described as being " in the Firth of Forth," whereas the Bell 

 Eock is 13 or 14 miles north by east of Fife ISTess, the 

 extreme limit of the Forth estuary on the north side. 



