112 CRUSTACEA. 



Great Britain and Ireland (see Thompson and Coldstream in 

 the Edinburgh New Philosophical Journal, 1834), and France. 

 From Coldstream's elaborate paper, just referred to, it is evi- 

 dent that the boring of this httle insect in the wood has for 

 its object the obtaining a supply of food, as "the contents of 

 the stomach resembled comminuted wood," and that it com- 

 mences its ravages on an entire piece of wood by fixing u])on 

 the soft parts situated between the hard annual layers, and 

 by subsequently working upwards at an angle of forty-five 

 degrees, keeping in preference in the course of the soft layer 

 into which it bored at first : the mandibles appear to be its 

 chief tools. It likewise appears necessary that the hole 

 should be filled with salt water while the insect is at work. 

 Very often, however, the galleries are horizontal, and some- 

 times perpendicular, the walls being as smooth as if cut by a 

 sharp knife. 



A paper by the Rev. F. W. Hope, contained in the second 

 number of the Transactions of the Entomological Society, 

 may also be referred to, in which several useful remeches are 

 suggested. I would also suggest the probabihty, that the 

 immersion of wood to be employed in submarine works in 

 Kyan's patent solution, would also be very serviceable. 



The majority of the species of the family Cymothoida are 

 parasitic upon various kinds of fishes inhabiting the ocean, 

 to which they attach themselves by means of their strong- 

 hooked feet, and then suck their blood ; hence the ancients 

 gave them the names of CEstrus and Asilus, from the re- 

 semblance between their habits and those of the breeze flies. 

 On the under side of the body of the females are fixed several 

 membranous pectoral imbricated scales, covering the eggs, 

 and in which the young are hatched. The type of the genus 

 Cymothoa is the Oniscus oestrum (Linn.), a species known 

 to Aristotle, who says of it — " Fishes are attacked by a sea- 



