LERN.EOIDEA. 



1381 



more nearly transversely than in the preceding, and are as long as 

 the caudal spines. 



Individuals of this species were very abundant, in latitude 6° north, 

 longitude 180°, on the 24th of May, 1841. Length, one-fortieth of 

 an inch. 



Figures 11 a, 6, c, represent a very different kind of animal. It has 

 a carapax like a neatly curved hemisphere, flattened in 'front, and 

 with slightly projecting anterolateral angles. In a lateral view, the 

 extremity of the abdomen projects a little, and below the middle of 

 the body the extremity of the trunk is seen. There is a single eye 

 on the medial line near the front. 



The abdomen is short and obtuse, and resembles much the abdo- 

 men of Conchoecia, so nearly, indeed, that we might suspect the 

 animal to be young of a species of that genus, if the character of the 

 mouth and shell were consistent with such a view. It has two series 

 of short spines, the terminal pair being the longest; and above these 

 a short distance there is another spine, as seen in the profile view. 



The mouth has the form of a large trunk, which is truncate and 

 broad at the extremity, and has a short spine at the angles of the ex- 

 tremity, with a ciliate margin between. The exact nature of this 

 trunk we do not understand. 



There are six pairs of jointed appendages, two antennary, one pair 

 probably maxillary, and one pair corresponding to a pair of feet. 

 The antennae are five-jointed and setigerous; the third joint is largest, 

 being broad and nearly obovate. The second and third pairs are two- 

 branched. The base of the second has an oblique process directed 

 inward, below, and furnished with short setae, which resembles the 

 inner process of a maxilliped, and shows the normal relations of the 

 legs to a pair of maxillae, if not to the mandibles. One of the branches 

 has five very short transverse terminal joints, and is furnished with 

 longish setae. The other branch is three-jointed and setigerous; the 

 first joint of the three has a short process on the posterior side. The 

 third pair has two equal three-jointed branches on a stout' base, and 

 the setae of the two are nearly equal in length. The length of the 

 animal was one-fortieth of an inch. 



Found abundantly off the north side of Upolu, February 24th 

 1841. It is provisionally named by the author Aspistes scabricaudis. 



