BRACIIVCRI. 191 



Pun XL) 



Flo. 10. Cancer (Pimurftow) rvf<r*m, prolific female. 



1 1. The same, having discharged tho roe. 



12. The name when dead, apron, a, unfolded. 



13. Antenna:, enlarged, a. 



B. The preceding Decapodes, or Ten-footed Brachyuri, though not 



.irr:in_"-<l in tin- sum- .mitiini'-l. imiiit.-iTii|'!'-'l lin,-. ;uv nr\ , : 1 1,, |, 

 fiiuiected by many all'mities, especially the absence of angular pin-Ik 

 the presence of short antennae, and other features. 



But there are also some Decapodc Brachyuri with long antenna?, with 

 all the feet complete, or tho hind pair abortive, which may be advert.-.! 

 to in passing. 



From the abortive hind feet, however, there are naturalist* who, 

 with sufficient plausibility, reject the following two species from the 

 Decapodes, considering them as furnished with only six real limbs be- 

 sides the claws. 



(1.) CANCEB (FORCELLANA) LONGICORNIS The Ventilating Crab. 

 Plate XLV. 6gs. 1, 2, 3, 4, 6, 6, 7, 8. 



This is the smallest of the Scotish Crabs that has come under my 

 \ i-\v. It is of orbicular form ; the body of many is perfectly so, about 

 four linen, or the third of an inch in diameter : the expansion of the 

 limbs also, is about an inch and a half ; the hind pair of different struc- 

 ture from the rest, are not always visible. Nothing peculiar charac- 

 terises the others, unless the great size and inequality of the claws of 

 certain specimens. Nevertheless this, with some minor features, renders 

 it doubtful whether there are not actually two species to be thu <lw- 

 tinguished. 



A. Claws nearly equal ; Spinous ; Limbs Spinous. 



B. Claws unequal, one double the size of the other. 



The eyes project in front like those of the Paguriu. Nothing pe- 

 culiar appears in the two internal short antennae. The external antennae 

 are long, being equal to three diameters of the body. 



