326 CRUSTACEA. 



guished from the rhombea and arenaria by its nearly naked legs ; and 

 from the cordimana in not having the lower margin of the larger hand 

 dentate or denticulate, as well as in the other legs, which are wholly 

 unarmed. The hands have a very smooth look, the upper margin is fine 

 granulate like the outer surface; the vertical crest on the inner surface 

 is naked. The surface of the sternum behind the mouth bears a few 

 short hairs. The anterior angle of the carapax is in the same line 

 with the inner part of the superior orbital margin. 



2. Ocidi pedunculus apice productus. 



Octpoda brevicornis, Edwards. 

 Plate 20, fig. 3 a, female, natural size ; &, eye of another female. 

 Feejees or Tongatabu. 



Length of carapax of a female (the eye of which is represented in 

 figure b), sixteen and a half lines; greatest breadth (across the line of 

 the anterior angles), nineteen lines; ratio, 1 : 1/15. Another speci- 

 men (fig. a), length, fourteen lines; breadth, sixteen lines; ratio, 

 1:1-14. 



The specimens referred to this species are females. They have the 

 short ophthalmic horn of the brevicornis, its length being about a fourth 

 as great as the rest of the eye or less. The hand is closely granulous, 

 the granules small and hardly pointed; the length anterior to the 

 fingers not greater than breadth of same. The fingers are flattened 

 and tapering. The anterior surface of the fifth joint on the second 

 and third pairs has but one dense line of hairs, and sometimes another 

 much less distinct. The outer maxillipeds are also similar, the third 

 joint being longer than broad, and the surface near either margin 

 being granulous. The small prominence within the orbit near its 

 inner limit, a short distance from the outer antennae, is denticulate. 



How far the length of the horn admits of variation in a species, we 

 cannot decide from the facts within our knowledge. It is possible that 

 the pallidida is only young of this species. 



In one specimen (that represented in figure 3 a), the eye termi- 



