135 



are covered by a projecting portion occupying a considerable part of 

 the back of the carapace and raised above it ; tbis projecting part is 

 environed by a somevvhat lyre-shaped wall, pinched in front on the 

 sides and somewhat notched bebind with two deep fossae placed 

 transversely and connected by a short eanal, the base of which is 

 smooth with only a few groups of warts. 



The abdomen is very regular and complete for the group, and when 

 additional specimens will admit of its being dissected, its structure 

 promises to be curious ; the various parts of it are hardly perceptible 

 in the individual examined ; a tolerably regular series of strange, close- 

 plaeed appendages on its edges, seem, on cursory observation, very 

 curious : there are about 1 2 deepish fossse over it, the 2 deepest in 

 the basai portion close to back part of carapace, and almost at right 

 angles to the ręst of abdomen, 3 on each side diverging into smaller 

 fossulee toward8 the edges, and four down the centre. The figures, 

 drawn by Mr. Westwood from the specimen, before it came into 

 Mr. Bell's possession, show asmuch as can be shownwithout injuring 

 the rare example. 



I exhibited a drawing of this crab at a meeting of the Linnean 

 Society some two years ago, and not having the specimen by 

 me, concluded, as Mr. Westwood's dravping showed it, that there 

 were no visible traces of the imperfectly developed leg-appendages, 

 so prominent in some species of Lithodes. A subsequent examina- 

 tion of the specimen kindly sent me by Prof. Bell has shown me I 

 was mistaken ; and on removing the carapace, vvhich Mr. Westwood 

 did, they are to be seen concealed as represented in the figure. There 

 is, however, no outward opening. 



This fine species is named Lithodes {Petalocerus) Bellianus in com- 

 pliment to the ablest of our British carcinologists, the learned and 

 scientific President of the Linnean Society, Professor Thomas Bell ; 

 in whose :fine coUection it is preserved. It is to him I am indebted 

 for the loan of the specimen. 



The plate represents — 



1. Lithodes {Petalocerus) Bellianus, of the natūrai size, viewed 

 from above. 



2. The šame from beneath, showing the pitted abdomen. 



3. Rough sketch of carapace in profile. 



4. Profile view of rostrum, with eyes, antennae, &c. 



5. Outer antennse with petaloid processes. 



6. Inner anteimae. 



7. Hind pair of legs, concealed under the carapace. 



8. Jaw feet. 



May 27, 1856. 

 Dr. Gray, F.R.S., in the Chair. 

 Mr. Gould brought under the notice of the Meeting a portion of 

 the Birds coUected by Mr. John MacGillivray, the naturalist at- 



