some British Fossil Crustacea. 171 



nuchal sulcus ; pterygostomian regions marked with large lon- 

 gitudinal furrows and a few rows of sharp granules ; surface 

 minutely granulated. Length from 9 lines to 1^ inch. 



I suspect that the figures in MantelPs ' Geology of Sussex/ 

 t. 29. figs. 15 & 16, and possibly 9 & 10, may belong to this spe- 

 cies, though rather more elongate than the specimens I have 

 seen. The N. Bechei (Deslong. sp.) is broader, more quadrate, 

 and has vertical rows of tubercles on the branchial regions. I 

 have a sincere pleasure in dedicating this species to the indefa- 

 tigable geologist, who in one of the earliest of his many valuable 

 geological works, has given the only figures I believe extant of 

 all the species of the genus. 



Not uncommon in the greensand of Lyme Regis and in the 

 gault of Folkestone. 



{Col. University of Cambridge.) 



Pagurus ? platycheles (M'Coy) . 



Sp. Char. Hands nearly equal, very much compressed, broad 

 ovate, width nearly three-fourths the length, the moveable 

 finger little smaller than the other; carpus trigonal, not so 

 long as wide ; surface closely covered with very obtuse granules 

 of unequal sizes. Length of left hand 10 lines, of right hand 

 8 lines ; width of left hand 7 lines, of right 5 lines ; length of 

 carpus 4 lines, width nearly 5 lines. 



One interesting specimen in the collection at Cambridge shows 

 the two strong crustaceous hands in situ, while all trace of the 

 body and abdomen have disappeared, which could scarcely have 

 happened unless, as in the recent Hermit Crabs, those parts 

 were almost membranous; close under the right hand is a 

 clear sparry cavity apparently indicating the place occupied by 

 the soft perishable abdomen. The granulation of the surface 

 resembles that of an Echinus. The species is remarkable for 

 the width and brevity of its hands and wrists. 



Not uncommon in the great oolite of Minchinhampton. 



In connection with the group Anomura I may say a few words 

 on a crustacean described and named Ammonicolax longimanus 

 by Mr. Pearce (see Annals for September 1842), which he sup- 

 posed to form a new genus of Hermit Crabs inhabiting the 

 Ammonites. It seemed to me very incautious to infer that the 

 Ammonicolax lived in the Ammonites on no better ground appa- 

 rently than their co-existence in the Oxford clay at Christian 

 Malford, and on recently examining two authentic specimens 

 presented by Mr. Pratt to the University collection at Cambridge, 

 I found that so far from being anomurous, the species had a well- 



