ME. E. J. ariEES OIT THE IDOTEID^. 49 



This species is marked witli olive or purple on a paler groiind, 

 the middle line of the back usually remaining pale. The median 

 tooth of the posterior margin of the last segment is often 

 obsolete. 



This species occurs in the Mediterranean, on the shores of 

 Great Britain and Ireland, Netherlands, Denmark, &c. ; but its 

 range is apparently not coniiued to the seas of Europe, since 

 there are specimens said to be from Java in the Paris collection, 

 and it is mentioned by M. Brulle in his list of the Crustacea of 

 the Canaries. 



There are male, female, and young specimens of this species in 

 the British-Museum collection from Ilf racombe, Devon (Dr. Leach 

 and Col. Montagu), three males from Beerhaven (Sir P. Egerton), 

 three from Northumberland (purchased), one found among shrimps 

 in the London market (P. Moore), and two or three, without 

 special indication of locality, from European seas. All of the 

 above are preserved dry. 



Of specimens preserved in spirit, the Museum possesses two 

 males from Ilfracombe (Dr. Leach), one from Ballinskelligs Bay, 

 Ireland (Sir P. Egerton), and several without special indication 

 of locality. 



In the Paris collection are many specimens from Algeria 

 (M. Lucas), the specimen (a small one without locality) that 

 served as type to the description of M.- Edwards in the ' Hist. Nat. 

 des Crustaces,' and others said to .be from Java (M. Eaynaud, 

 Exp. de la Chevrette), with a specimen in fragmentary condition 

 apparently referable to /. marina. 



S. Bate and "Westwood are, I think, in error in referring Armida 

 viridissima, E-isso, to this species ; on the other hand, the de- 

 scription of A. himarginata applies very well to those varieties 

 of it in which the median terminal tooth of the postabdomen 

 is developed. 



To this species undoubtedly belongs a specimen in the Linnean 

 Cabinet labelled linearis ; the quadridentated appearance of the 

 terminal postabdominal segment was caused apparently by the 

 slightly projecting inferior and posterior angles of the opercular 

 valves, which are visible from above in a dorsal view. The habitat 

 " Surinam " is given in the 12th edition of Linnaus's work ; but 

 in Linnseus's copy in the possession of the Society the MS. 

 words " in Oceano Ailantico " occur, with a line drawn through 



LINN. JOURN. — ZOOLOGY, VOL. XVI. 4 



