3686 Crustacea. 



of Natural History.' Suffice it then for the present to give the fol- 

 lowing, in the order and with the names assigned to them in White's 

 ' Catalogue of British Crustacea.' 



The Common Sand-hopper, and Shore-jumper, Talitrus Locasta 

 and Orchestia littorea, are to be met with in great abundance upon 

 the sandy beaches, at and above high-water mark, by hastily remov- 

 ing the masses of half-sunken half-decayed debris thrown up by 

 the tide. 



The Common Coast-screw, Gammarus Locusta, is everywhere to 

 be found about the sea margin and brackish water, and is well known 

 under the provincial name of " Sea-louse." Other species of this, or 

 of nearly allied genera, have been observed about the Firth. 



The Long-horned Mud-liver, Corophium longicorne, swarms in the 

 brackish waters of the canal of the Loch of Spynie and of the Bay of 

 Findhorn. The eastern banks of this Bay have often a white line, 

 like drifted snow, formed on them almost entirely of the cases or outer 

 skeletons of this singular-looking species. 



Hyperia Latreillii. Bay of Findhorn, August, 1852. Some small 

 Crustaceans, collected from two large Medusae, most probably belong- 

 to this species. There were many other smaller Medusae lying on the 

 same part of the beach, and differing only in size from the two to 

 which the parasite seemed confined. Here the parasite was of a 

 higher grade in the scale than the animal on which it lived. 



Muller's Spectre Shrimp, Proto pedata. From its frequent occur- 

 rence as part of the food of the haddock, the spectre shrimp seems to 

 be abundant in the fishing-grounds of the Firth. 



Sowerby's Arcturus, Arcturus longicornis, and Goodsir's Arcturus, 

 A. gracilis, are also abundant. 



Some forms of Idotea have been collected ; but to which species 

 they belong has yet to be determined. 



The Boring Limnoria, Limnoria terebrans, so destructive to tim- 

 ber, is not rare in this northern arm of the sea, but is found both in 

 the fixed and floating pieces of wood. 



The Common Land Slater, Oniscus Asellus, " Sklater," is the only 

 inland Crustacean that has yet been met with in this district, and 

 compared with the scientific descriptions in systematic works. 



Cranch's Fish-louse, Cirolana Cranchii, is occasionally found as a 

 parasite on the cod. The numbers of this species that have been seen 

 in the stomach of the haddock, show that it is not rare. 



The Nebalia, Nebalia hipes. Only two or three specimens have 

 been obtained : but its minuteness may account for its seeming rarity. 



