BRAOHYURI. 191 



Plate XLV. 



Fig. 10. Cancer (Pinnotheres) veterum, prolific female. 



11. The same, having discharged the roe. 



12. The same when dead, apron, «, unfolded. 

 IS. Antennae, enlarged, a. 



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

 arranged in the same continued, uninterrupted line, — are nevertheless 

 connected by many affinities, especially the absence of angular shells, 

 the presence of short antennjB, and other features. 



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

 all the feet complete, or the hind pair abortive, which may be adverted 

 to in passing. 



From the abortive hind feet, however, there are naturalists who, 

 with sufficient plausibiUty, reject the following two species from the 

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

 sides the claws. 



§ (1.) Cancer (poRCELLiS-NA) longicornis — The Ventilating Crab. — 

 Plate XLV. figs. 1, 2, 3, 4, 5, 6, 7, 8. 



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

 view. It is of orbicular form ; the body of mau}' is perfectly so, about 

 four lines, 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 diflferent 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 thus dis- 

 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 Paguriis. Nothing pe- 

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

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



