PARALOMIS. 45 



species is congeneric with Echinocerus cibarius White.* He therefore proposes 

 to treat Paralouiis as a synonym of Echinocerus in a paper soon to be pubHshed. 

 The two " Challenger " species referred to Paralomis by Profes.sor Hender- 

 son t are, as Mr. Benedict points out, generically distinct from P. granulosa. 

 In the latter the ambulatory appendages are comparatively short (not very 

 much longer than the chelipeds) and are tucked in nnderneath the body 

 during repose, while in Henderson's species the ambulatory logs are very 

 long (much longer than the chelipeds) and are not capable of folding com- 

 pactly beneath the body. 



After a careful examination of Paralomis granulosa I am disposed to 

 recognize the genus P«;v//o;«?s as distinct from Echinocerus, and furthermore 

 to assign Echinocerus diomedece of my preliminary report to Paralomis. In 

 Echinocerus as exemplified either in the type species, E. cibarius, or in E. 

 foraminatus Stimps., the ambulatory legs are about the same length as the 

 chelipeds and fall below the lateral dimension of the carapace ; not only do 

 all the legs fold imder the body but their segments are so modified that in an 

 attitude of repose all of the opposed surfaces and edges are fitted together 

 with admirable nicety, and the animal is boxed up as effectually as a tortoise 

 in its shell. The dactyle of the left cheliped shuts over the dactyle of the 

 right as in Calappa and, as in that genus, the immobile fingers are shortened 

 and bent down so that their cutting edges are nearly at right angles with 

 the long axis of the chel« ; the outer edge of the left dactyle fits throughout 

 its whole length exactly against a tuberculous ridge along the anterior bor- 

 der of the right hand. The antero-inferior angle of the merusis bevelled off 

 for the reception of the chela when flexed, so that the exposed face of the 

 chela is then on a level with the flat expanse formed by the sternal plastron 

 and the bases of the ambulatory legs. Furthermore, a special process devel- 

 oped on the anterior border of the basal segment of the chelipeds locks the 

 tips of the chelipeds to the sternum when those appendages are folded in. 

 In order that the ambulatory legs when flexed may not project below the 

 level of the sternal plastron, their meral segments are set at an angle with 

 the ischia, whose inferior distal borders are raised into prominent lidges. 

 The propodites and dactyli, when folded, impinge on these ridges, but hardly 

 project beyond them. 



* Proc. Zoolog. Soc. London, XVI. 48, 1848. 



t Paralomis aculeala Hend,, Rep. Challenger Anomura, p. 4.5, PI. V, Fi?. 1. and P. formosci Hend., 

 op. cit., p. 46, PI. V. Fig. 2. Tlie two species assigned to Paralomis in my prclimiuarv report, P. asperu and 

 P. lonr/ipes (Bull. Mus. Comp. Zobl., XXIV. 164, 165) belong to the aculeata group, which Mr. Benedict 

 proposes to call Leptolithodes. 



