102 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [396] 



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brown, and often annulated with brown, or with gray and white. It 

 differs from all the other American species in having a short, acute ros- 

 trum, scarcely projecting beyond the eyes, with three or four sharp teeth 

 on its upper edge and none below. In form and general appearance it 

 somewhat resembles the Virbius represented in Plate III, fig. 11, but is 

 stouter and quite different in color. It is a northern species, extending 

 to Greenland and Northern Europe, and is more common on the coast 

 of Maine, where it is usually associated with several other larger species 

 of the same genus, all of which are remarkable for their brilliant colors, 

 the various shades of red usually predominating. Their bright colors 

 are no doubt directly connected with their habit of living among the 

 bright red alg3, so abundant in the shallow waters on rocky bottoms. 



A beautiful little shrimp-like Crustacean, Mysis Americana SMITH, 

 sometimes occurs in immense numbers among the algae growing on the 

 rocks just below low-water mark, especially in spring. This is an im- 

 portant species, as it is one of the principal kinds of food for the shad 

 and other fishes. The full grown specimens are only about an inch long. 

 It is almost transparent, whitish, with conspicuous black eyes ; there is 

 a row of more or less conspicuous, dark stellate spots along the body, both 

 above and below, and similar specks often occur on the tail ; a spot of 

 dark brown or blackish often occurs on each side of the carapax. The 

 intestine shows through as a greenish or brownish line. 



Another small, shrimp-like species belonging to an interesting new 

 genus, the Heteromysis formosa SMITH, often occurred in small colonies, 

 sometimes hid away in the dead shell of some large bivalve or gastro- 

 pod. The females of this species are of a beautiful light rose color, but 

 the males have the pale color and translucency common to most of the 

 species of Mysis. 



Numerous Amphipods also occur, most of which are also found iii 

 the pools or under stones at low water, and have, consequently, been 

 mentioned on former pages. One of the most curious Amphipods 

 was a small species, found living among the large compound ascidians, 

 which is probably Cerapus tiibularls SAY. This species constructs 

 a little, slender, free tube, which it inhabits and carries about 

 upon its back when it travels, very much as the larvae of caddis-flies, 

 common in fresh waters, carry about their tubes. One species of bar- 

 nacle, the Balanus crenatus, was abundant, often completely covering 

 small stones and shells. This has not been met with, as yet, at low- 

 water, although it occurs on the bottoms of vessels. 



Of Annelids a large number inhabit rocky bottoms, but as most of 

 them live beneath the rocks, or in tubes attached to rocks and stones, 

 it is difficult to obtain an accurate knowledge of them. Many of the 

 species seem, however, to be found also in pools and beneath the stones 

 on rocky shores, and have already been mentioned. 



Perhaps the most characteristic Annelids of rocky bottoms are the 

 scaly worms, of which three species are common in this region, viz. : 



