Rev. Canon A. M. Norman on Lepton squamosum. 277 



mosnm, and the circumstances under which it occurred were 

 remarkable. I was digging on the eastern side of the harbour 

 in the hope of finding Callianassa subterranea, the parasite of 

 which, lone thoraciea, I was especially anxious to procure. 

 I did not succeed in finding the Callianassa, but came across 

 large numbers of the long passages formed by Gebia stellata, 

 the mouths of which passages opened into the sides of little 

 pools in the muddy sand at about half-tide. In every case 

 where the burrow was still occupied by the living Gebia I 

 found in the burrow and at a short distance from the mouth 

 one, or in some cases two, living Lepton squamosum. The 

 burrows of the Gebia are lined with an ochreous-coloured 

 slimy deposit, and upon this it seems probable that the Lepton 

 feeds. Here, then, would seem to be a case of comraen- 

 salism. These observations of course require verification, and 

 I trust any naturalists who have the opportunity of examining 

 the homes of Gebia will search within them for the Lepton. 

 It is worth remarking that the geographical range of the 

 ciustacean and of the mollusk are, as far as is known, the 

 same ; both occur in the Mediterranean, for the Gebia litoralis 

 of Risso is synonymous with G. steltata, Montagu, and both 

 reach Scandinavia, in which country the Lepton has long been 

 known and recently the crustacean also has been found. 



The only malacologists who have observed the animal of 

 Lepton in Britain are Alder and Clark, the first of whom 

 procured his specimen at Salcombe and the latter near Ex- 

 mouth, where, from the nature of the shore, we may pretty 

 safely predicate that Gebia also lives. 



A striking confirmation of the view here put forward of the 

 commensalism of Lepton squamosum is to be found in a 

 passage in Jeffreys's ' British Conchology,' vol. li. p. 194. 

 He writes : — " A species (Lepton loripes) } half an inch long, 

 found on the coast of Florida has a singular habitat. According 

 to Mr. Stimpson, the discoverer, ' it lives in sand or mud, on 

 the flats, near low-water mark, at the depth of a foot below 

 the surface, and generally occupies the holes of marine worms 

 and fossorial Crustacea.' This might warrant a supposition 

 that the animal of Lepton is predaceous." To this remarkable 

 confirmation of the habits of the species observed by me at 

 Salcombe I may add that the very same genera of fossorial 

 Crustacea which live at the latter place are those which occur 

 also on the Floridan coast, where they are represented by 

 Callianassa major , Say, and Gebia affinis. Say. 



Of course I cannot acquiesce in Dr. Jeffreys's concluding 

 supposition that " the animal of Lepton is predaceous," if 

 indeed, by that expression he meant that it would attack the 



