BRACHYURI. 195 



D.— 2. Hyas akanetjs.— Plate XLVII. 



Dr Leach quotes from authors by whom this subject is named 

 Cancer main, Inachus, and Ilt/as by himself, whereof he says there are 

 two British species, Hj/as arancus and Hi/as coardatus. It is to the 

 former that the attention of the reader is now directed. 



Excepting the Cancer horridm, the Lithodes mala of the last named 

 author, the subject of the present paragraph is the largest of the trian- 

 gular crabs inhabiting Scotland. 



The Cancer or Hyas araneus appears under much variety of aspect, 

 so great, indeed, that were there varieties, I should almost doubt 

 whether the two represented in the following plates, shall be identified 

 with those of preceding authors. But such varieties may be incidental 

 to age, or sex, or position : and, as already signified more than once, the 

 ductility of matter, especially of organic matter, affords distinctions 

 often requiring search by a miscroscopic eye. 



Length of the body, towards three inches ; extreme breadth, under 

 two. Expansion of the limbs, which are long, rather slender, and 

 armed with nails, six or seven. Two eyes, each borne on a peduncle, 

 incline from the sides of a solid rostrum. — Plate XLVII. fig. 1 ; XLVIII. 

 fig. 1. The apron, thorax, or abdomen of both sexes is large, of an irre- 

 gular quadrangular form in the male, Plate XLVII. fig 2 ; and that of 

 the female, somewhat resembhng an irregular hollow spherical segment. 

 —Plate XLVIII. fig. 2. 



Many thousand ova have elevated the apron as early as the middle 

 of February, and thence forward to the middle of July. At the latter 

 season, the animals are full of roe, protruding from under the edges of 

 the apron. In far advance, this substance consists of fine luxuriant 

 reddish-orange clusters, each capsule attached to a principal stalk by its 

 own pedicle, and each of these stalks to one of still superior dimensions, 

 so that the aggregate forms a cluster. 



This is an extremely languid and inactive animal, far from interest- 

 ing to view, for many hold its appearance to be very repulsive. 



Deep water seems the proper dwelhng of full-grown specimens ; 



