12 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



parts which are impregnated by iron rust from spikes, etc. When 

 abundant it will destroy soft timber at the rate of half an inch 

 a year, thus reducing the diameter of a pile, for example, by 

 one inch in that time. On the average, however, the rate of de- 

 struction is only about half of this. As early as 1875 Andrews 

 observed Limnoria attacking the gutta percha of submarine tele- 

 graph cables. (Quart. Jour. Micro. Sci., ser. 2, vol. 15, p. 332, 



1875.) 



The holes made by this Isopod are nearly round and may be a 



sixteenth of an inch in diameter. They go into the wood at all 

 angles and are usually more or less crooked. The species is con- 

 fined to a rather narrow zone extending- a short distance above 

 and below low-water mark. The burrows are made by means of 

 the stout mandibles and the excavated material is eaten ; thus 

 the burrow affords the animal both food and shelter. 



The remedies against this animal are chiefly copper, or other 

 metallic sheathing, broad-headed iron nails driven close together, 

 and coal tar, creosote, or copper paint applied to those parts 

 which are liable to be attacked. 



Certain of the terrestrial Isopoda also damage vegetation 

 to some extent by feeding upon the more tender portions of 

 plants. In Louisiana and Texas Armadillidium vulgare, accord- 

 ing to Miss Richardson, is a menace to cucumbers and other 

 plants grown in hot houses as well as to young cotton, and in 

 Virginia it is " one of the most destructive pests with which 

 the mushroom grower has to deal." 



Besides the roles already mentioned, the Arthrostraca 

 are important as food for certain fishes, forming, with the 

 shrimps, a very large part of the food of most of our more 

 valuable edible fishes. Professor Verrill states that the Amphip- 

 oda occur in such immense numbers that they can nearly always 

 be obtained by the fishes that eat them, and that the voracious 

 blue fish feed upon them even when menhaden and other fishes 

 which they prey upon are plentiful in the same neighborhood. 

 Among the species of Amphipoda taken from the stomachs of 

 porgies, torn cod, and herring caught at Woods Hole and New 

 Haven, large numbers of Unciola irrorata, Ampelisca sp? 

 Gammarus annulatus, G. locusta, Calliopius Iceviusculus and 

 Leptocheirus pinguis have been recorded by Verrill. 



