THE CRUSTACEA 153 



The size of the male is about three and a half inches 

 broad by two and a quarter in each other direction. It 

 lives on muddy ground, and is not often taken on shores, 

 but is pretty frequently taken by dredge and trawl. 



Let us now digress a little, and wander into the fields of 

 deduction, to ascertain, if possible, the place in nature of 

 this division " Anomoura." 



Let us go back to Callianassa (p. 129), and note its 

 structure, and habit of now and then utilising the burrow 

 of a worm or other animal to protect its tender parts, then 

 postulating tentatively some ancestral form of Callianassa 

 that could not always find burrows to let when it was 

 on ground too hard to tunnel. The next best accommoda- 

 tion they would find would be empty univalve shells. 

 They would force themselves into these. Those that 

 managed this best would have a chance in life, and would 

 transmit to their offspring their plasticity. They would 

 gradually modify their form to suit the new conditions. 



" Each fashion of life with reflex forcible action would 

 act on the form," and in the course of time the " Hermit " 

 type would be reached, for the telson would at first bend, 

 then become hinged. The legs that protruded would be- 

 come large and strong by use, and by having a shell to 

 drag about. Then some of the hermits, yielding to further 

 developments of conditions, would find, no doubt with 

 " Hobson's choice," that a tucking under of the tail and a 

 development of defensive spines, etc., would enable them 

 to live on. Thus the Lithodes and Galaihea, etc., types would 

 be arrived at. So that the anomoura would seem to be, 

 not a form transitional between the long and short tailed 

 crustaceans but a strangely erratic offshoot of the former. 



I set this out at length in an illustrated article in Life 

 Lore for August 1889, but am told that the same conclusion 

 has been arrived at by some naturalist who has also pub- 

 lished the results of his observations. This publication I 



