370 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



The Jllysis stenolepis Smith, (Plate III, fig. 12, female,) is often very 

 abimclant in sucli situations. The small young ones have been taken in 

 May, and the half-grown ones later in the season. In the early spring 

 the adult females, with eggs, occur in great numbers among the eel- 

 grass, in estuaries and ponds. Mr. Yinal N. Edwards caught a large 

 number in a small pond at Wood^s Hole, April 1. ]^o males were found 

 at this time with the females; the only adult males observed were taken 

 in autumn. Possibly the males do not survive the winter. The adult 

 females have not been observed in summer, and they probably die after 

 hatching their young in the spring. The whole body is translucent ; 

 each segment of the body has a stellate black spot ; and there is more 

 or less blackish j)igment on the caudal lamelkT, telson, anteunal scales, 

 and inner flagellum and peduncle of the antennulte. This species con- 

 tributes largely to the food of many fishes. The other species, il/. Amcr- 

 icana Smith, also lives among eel-grass, as well as in deeper water oft" 

 shore among algi^e. This has been found in large numbers m the stom- 

 achs of the shad and the spotted flounder. 



Of Amphipods there are comparatively few species. The Unciola 

 irrorata (p. 340, Plate lY, fig. 19) is pretty common here, as elsewhere. 

 The Am]}Mtlw(i valida S311TH (p. 315,) is often met with among eel- grass. 

 Another species, A. compta Smith, also occurs in the same places. 

 It differs from the preceding in many characters, but may easilj^ be dis- 

 tinguished by its red eyes. A third species of the genus, ^l. Jonglmana 

 Smith, is also found among eel-grass. It has black eyes. The Cora- 

 pkiiini cylhidnctim and Gammarus mncro nat us oecuv among eel-grass and 

 algiie, often in great numbers. 



Of Isopods there are several species. The Idotea irrorata (p. 31G, 

 Plate y, fig. 23) is common wherever eel-grass is found. The Erichso- 

 nia attemiata Harger, (Plate VI, fig. 27,) is also found clinging to 

 eel-grass in muddy situations. The Upelys trilobus (Plate VI, fig. 28) 

 is found creeping about over the bottom or among and beneath the 

 decaying vegetable matter and mud usually to be found in sheltered sit- 

 uations. It is usually so covered up with adhering dirt as readily" to 

 escape observation. The Upelys montosus also occurs in similar situa- 

 tions. 



Whenever lumber or drift-wood has been left for some time on the 

 muddy shores it is found to be more or less eaten by the Limnoria lig- 

 norum, (Plate VI, fig. 25.) This small isopod gnaws its galleries in the 

 wood to a depth of about half an inch from the surface, and after a 

 time these galleries become so numerous that the superficial layer will 

 be completely honeycombed, and it will then scale off and another layer 

 will be attacked. This little creature often does great damage to the 

 piles of wharves and other kinds of submerged wood-work in this re- 

 gion, and will be mentioned again in discussing the animals inhabiting 

 piles, &c. 



The "horse-shoe crab,'' LUnidns rolyplicinus, (p. 310,) is also common 



