170 J. MURRAY 



42 fi long, claws 20 M- Eyes dark. The dots on the skin are irregularly placed, 

 but at very nearly equal spaces. They are not pigment spots, but appear to be 

 minute elliptical pieces of the same nature as the skin, set into it like buttons in a 

 cushion, and looking dark from the different refraction of the light. The reddish 

 colour is confined within the body fluid, and is resident chiefly in the fat-cells, 

 though the fluid is also more or less coloured. There are two layers of skin, 

 between which there is enclosed a colourless fluid, in which float numerous thin 

 hyaline oblong plates. This may be a pathological condition, but it is noteworthy 

 that it occurred in all the individuals examined, old and young, and in none of the 

 other species present. 



The claws are like those of hufelandii, but more slender. Those of each pair are 

 unequal in length, and are united for half the length of the larger one, which bears 

 the usual two supplementary points. 



The basal ridge, which in M. coronifer bears the " corona " of little spines, is 

 in this species irregularly dentate. 



The processes of the egg are separated by interspaces greater than their own 

 diameter at the base. They have narrow conical bases, and taper to slender points 

 which are curved over. 



The gullet is about 4 n in width, but is rather narrower below and expanded 

 towards the pharynx. The rod next the gullet is about three times as long as 

 broad, the second about twice as long as broad. 



Habitat. Among moss from the sea-shore, little above high-water level, at 

 Victoria, British Columbia ; very abundant, eggs also abundant. 



M. occidentalis appears to have its closest affinities with that group of northern 

 species of which M. coronifer may be regarded as the type. Several of these species 

 have a spinose ridge in front of the claws, most distinct on the fourth legs. In 

 M. coronifer and M. granulatus the ridge bears spines in M. crenulatus it is 

 wrinkled in M. harms^vorth^ it is crenate or plain. In large examples of M. 

 occidentalis the ridge is dentate (Fig. 54d). 



Several of the northern species have distinctive colouring, resident in the fat-cells. 

 M. coronifer and M. islandicus are bright yellow. The colour of M. occidentalis 

 is more inclined to red. As in M. coronifer, the colour is present even in the egg. 

 In the egg it is darker, and more distinctly red. It cannot then be resident in the 

 fat-cells. The body fluid itself is in old animals of a yellowish colour. 



The processes of the egg have some resemblance to those of M. coronifer and 

 M. islandicus. The egg of coronifer is elliptical, and the spines are straight ; 

 that of islandicus is round, but it has two sorts of processes, spines like those of 

 coronifer and processes like those of granulatus. M. occidentalis has longer and 

 more slender spines than either, and they are variously bent and turned over at 

 the ends. 



The pharynx is quite like those of coronifer and islandicus. On the whole the 



