372 A HISTORY OF RECENT CRUSTACEA 



occurs in the North Atlantic, Astacilla marionis, Beddard, 

 in the Southern Ocean. The young of this genus some- 

 times, if not always, have the fourth segment of the person 

 not elongate, just as in Archiriis. 



Family 2. — Idoteidoe. 



The body is ovate or oblong, or more or less oblong- 

 ovate. The mouth-organs and pleon and its appendages 

 are nearly as in the preceding family, but the maxillipeds 

 sometimes have the ' palp ' become three-jointed by coa- 

 lescence. The second antennse are not as a rule greatly 

 elongate ; the flagellum may be rudimentary, single- 

 jointed, or more usually multiarticulate. The limbs of the 

 peraeon are usually nearly alike, but the first three pairs 

 are sometimes subchelate, and the last two may be ' mul- 

 tiarticulate.' 



Glyptunotus, Eights, 1852, has the maxilliped-' palp ' 

 three-jointed, the two terminal joints being fnsed and also 

 the two that precede them. The first three pairs of limbs of 

 the pera=on have the sixth joint dilated and are subchelate. 

 The pleon has three or four complete sutures ; the stilets 

 on the second pair of pleopods in the male are very 

 elongate ; the outer branch of the uropods is minute. 

 Glyptonotus anta/rcticits, Eights, being ' dorsaliy sculptured,' 

 corresponds with the generic name. It attains a length of 

 three inches and a half by a breadth of an inch and three- 

 quarters, and is, therefore, one of the monster Isopods. 

 The Arctic species, which also occurs in the Baltic and the 

 depths of the Swedish Lakes, Gh/ptonotvs entomim (Linn.), 

 is not much smaller than the preceding. Ghiridutea, 

 Harger, 1878, is regarded by Miers as a synonym of 

 GlyptoTwtus. 



Ghcetilia, Dana, 1852. Mr. Miers, in his elaborate ' Re- 

 visionof theldoteidge,' says:—' The multiarticulate character 

 of the sixth and seventh thoracic legs is probably not a 

 character of the importance assigned to it by Dana. In 

 its ovate form, four-segmented postabdomen [pleon], and 

 elongated antennules, the relationship of Ghmtilia to Glyp- 



