316 EEPORT oT^liMMlSSIONER OF FISH AND FISHERIES. 



it loves to dwell. It is fouud iieaiiy up to high-water mark, and has a 

 wide range both northward and southward along the coast. 



Another very common and much larger isopod is the Idotea irro- 

 rata, (Plate Y, fig. 23,) which growls to be nearly an inch long. Its 

 colors are extremely varied. Often the general color is dark gray, light 

 gray, dull green, or brownish, thickly specked and blotched with darker, 

 but the colors are often brighter and the markings more definite; not 

 unfrequently a band of white, or yellowish, or greenish, runs along the 

 middle of the back, with perhaps another along each lateral border. 

 This species occurs creeping among the '' rock-weeds" and other algii? 

 at low water, in the pools, creeping on the under sides of stones, ad- 

 hering to eel-grass, and also among floating sea-weeds, away from the 

 shore, and in many other situations. Its colors are generally well 

 adapted for its concealment, by imitating, more or less perfectly, the 

 rocks and weeds among which it lives. Even those with bright green 

 markings are thus protected when living on eel-grass or Ulva ; the dark, 

 obscurely marked ones when on dead eel-grass or dark Fhcus ; the grays 

 and browns when on stones and among barnacles, &c. This protection 

 is not perfect, however, for they often fall victims to hungry fishes of 

 many kinds. 



The Idotea phospUorea Harger, is a closely allied species, which 

 grows even larger. It can easily be distinguished by the tail-piece, 

 which is acute in tbis, but tridentate in the last, and by its rougher sur- 

 face and more incised lateral borders. Its colors are similar and equally 

 variable, though they are frequently in larger and more definite spots 

 and blotches, and the light spots are often bright yellow. It is, as its 

 name indicates, decidedly phosphorescent. It lives under the same cir- 

 cumstances as the preceding species, but is much less common in this 

 region, though it is abundant in the Bay of Fundy. It often occurs 

 among the crowded stems of Corallina ofjUcinalis in the larger tide-pools. 



Another related species, the Urichsonia filiformls Harger, (Plate 

 YI, fig. 2G,) also occurs among the Corallina and other algiP in the tide- 

 pools. This is a smaller species than the two preceding, but is some- 

 what similar in its colors, which are equally variable and equally adapted 

 for its concealment ; in this the colors are more commonly various tints 

 of brown, or dull reddish, or light red, which are well adapted to blend 

 with the colors of the Corallines. Quite a difterent looking creature is the 

 Epchjs montosus, which is occasionally found concealed beneath stones 

 where there is more or less mud. This species also frequents muddy 

 bottoms, and is pretty effectually concealed by its rough-looking back 

 and the coating of mud and dirt that always adheres to it. 



Clinging to the hydroids and delicate algtie on the under sides of 

 stones, and in tide-pools, curious slender-bodied Crustacea belonging to 

 the genus Caprella (similar to fig. 20, Plate Y) may often be found in 

 considerable numbers, but they are still more abundant on rocky bot- 

 toms off shore. Thev have the habit of holding on firmly by the pos- 



