344 Dr. W. C. M'Intosh on the 



runlets, and on muddy ground. A group of young forms of 

 some size may sometimes be seen in company with their 

 parents. 



The first pair of foot-jaws have their two terminal segments 

 furnished with the longest hairs (proportionally) yet met with 

 in the local forms. The hairs have a double row of spikes, 

 diminishing towards base and tip, and cease before arriving 

 at the end of the hair, which has very fine linear serrations. 

 The external division has a powerful triangular, and some- 

 what tapering, lower segment, and a delicate appendage fringed 

 with a brush of spiked hairs at the tip. The second pair has 

 the external division much flattened, lanceolate, and with hairs 

 having spiked bases and serrated tips on the outer edge ; the 

 hairs also occur generally along the inner margin, and are 

 frequently sheathed in mud and particles of all kinds. The 

 third pair consists of three portions furnished with long branched 

 hairs. The fourth pair has the large flat shield surrounded 

 with branched hairs ; next is a curved tapering portion with 

 bristles having short spikes towards the tip; then come 

 a series of flattened organs with truncate tips covered with 

 spiked hairs. The fifth pair has three divisions — an inner 

 irregular portion with hairs shortly branched on its free edge, 

 a middle and somewhat club-shaped piece with rather stiff 

 serrated hairs scantily spiked at the base, and a curiously 

 curved and rather slender inner portion with about half a 

 dozen finely serrated hairs on one side of its tip. 



The hairs on the outer border of the chelae are densely 

 plumose ; and hence it is exceedingly difficult to clean them 

 from mud and sand for the cabinet. 



Porcellana longicornis, L. ; Bell, op. cit. p. 193. 



As common as the former, in similar, though not muddy, 

 situations. The embryos are found in the ova in August; 

 and many young occur under stones in November and 

 December. 



Fam. Lithodida. 



Genus Lithodes, Latr. 



Litlwdes maia, L. ; Bell, op. cit. p. 165. 



Not uncommon in deep water, whence it is brought by the 

 fishing-boats. 



