Ixxxvi NATURAL HISTORY. 



the Argonauta Arclica, are to be seen in every crack that opens with the tide, even at 

 the coldest period of the year. 



It is called by the natives Il-le-ak-kak. 



AMPHIPODA. 



8.— THEMISTO GAUDICHAUDII. 



Th. corpore elongate, luteo ; capite globoso ; antennis inferioiibus longioribus ; pedibus inaequalibus, quinto 

 pari longissimo ; cauda appendicibus planis, ciliatis. {Gu(r.) 



This singular animal was first described by M. F. E. Guerin, in a paper entitled 

 " Menioire sur le Nouveau Genre Themisto," kc, communicated to the Society 

 of Natural History at Paris, August 29, 1828, and published soon after in the fourth 

 volume of the memoirs of that society. 



The specific name is in honour of Dr. Gaudichaud, one of the naturalists of the 

 corvette La CoquiUe, during a voyage round the world, under the command of Captain 

 Duperrey, by whom it was collected, together with a number of other curious specimens 

 of maiine invertebrate animals. 



M. Guerin's minute and accurate description is exceedingly well illustrated by 

 a lithographic delineation of the various parts that compose this singular and 

 interesting genus. The individual selected for description was smaller than those met 

 with by us during our late voyage to the Arctic Regions, our specimens being as large 

 as M. Guerin's second or^magnified figure ; in every other particular they agree with 

 his description, of which the following is an extract : 



" Corps oblong, compose de douze segmens;* tete occupee entierement par deux 

 yeux a r^seau, arrondie, non prolongee inferieurement en rostre. Quatre antennes, les 

 superieures plus courtes que la tete, courbees au bout ; les inferieures beaucoup plus 

 longues. Quatorze pieds ; les quatre premiers courts, diriges en avant, couches sur la 

 bouche, et representant les deux dernieres paires de pieds-machoires des erustaces 

 superieurs; les quatre suivans beaucoup plus grands, termines par un crochet dirige 



• Not including the head. 



