77 



the animal is active, tliey are, 1st. The tip joints of the palpi of the 

 5th and 6th pairs of jaws. 2d. The whole of the 3d pair of jaws ; 

 each of which is in the form of a lobed, flattened, and almost mem- 

 branous plate, and, of this the true jaw moves rapidly in a lateral 

 direction, while the palpus, lying horizontally just at the mouth of 

 the branchial chamber, flaps briskly up and down to renew the 

 water for respiration. 4th. The interior pair of antenna? alter- 

 nately nod up and down. By all these motions a series of cur- 

 rents is kept up. The interior antenna? and eyes are occasionally 

 brushed with the larger pairs of jaws, somewhat in the manner of 

 a fly. The fifth pair of legs on the body are used to clean out the 

 branchial chambers. They are, from time to time, thrust into 

 the branchial chamber from behind, and are there moved about 

 and then withdrawn. The females had segmented eggs, carried 

 in a bunch on the left side of the tail. 



Gelasimus vocans. In immense numbers, both in ditches and 

 on flats of damp sand, where they make holes. Some were dig- 

 ging these holes, and the work seemed chiefly done by the males, 

 who, indeed, appeared more active than the females. In begin- 

 ning the hole, they simply thrust their legs into the sand and then 

 crowd themselves in sideways ; but, when the hole gets deep, they 

 bring out armfuls of sand, which they leave near the mouth, and 

 then return for more. Some seemed to collect bits of sea-weed, 

 &c., to line their burrows with. The legs used in digging and in 

 carrying the sand were the four on the side of the body opposite 

 the big claw. They always went into the burrow with the big 

 claw last. In walking, two alternate legs on a side are moved 

 simultaneously. There were generally a male and a female in 

 each burrow. The males had a singular habit of rearing up for 

 a moment on their hind legs, and holding up their claws and other 

 legs as high as possible, as if to enjoy the breeze. Saw none 

 fight, except one male, who tried for a long while to get another 

 out of his burrow, by seizing him with his big claw and dragging 

 him with all his might. No females with eggs noticed. 



Filumims Harrisii [?]. Among sea-weed, &c., in shallow 

 water ; pretty abundant. No females with eggs seen. 



Ewpagurus longicarpus. In little shells. 



Idotea cceca [?]. Little isopod, brown-olive or bright green. 

 Among sea-weed in plenty. 



