186 A HISTORY OF RECENT CRUSTACEA 



the last segment ; each side of this band the mottlings are 

 fewer, and the surface somewhat hairy. The last segment 

 and the appendages of the preceding one are thickly 

 specked with reddish brown ; their edges are fringed with 

 grey hairs.' Leach's statement that Upogebia stellata 

 makes winding horizontal passages in the mud, ' often of 

 a hundred feet or more in length,' appears still to await 

 confirmation. 



A second British species was named Gebia deltdura by 

 Leach, on the ground that the interior lamella of the tail- 

 fan is ' truncate and formed like the Greek Delta.' No 

 doubt he was alluding to the inner branch of the uropods. 

 This is an obscure feature on which to base the specific* 

 name, and Bell has been not unnaturally misled into sup- 

 posing that Leach was referring to the telson, which, how- 

 ever, is not at all deltoid in form, and which Leach himself 

 expressly describes as ' quadrate ' and ' nearly quadrate.' 

 According to Leach 'this species lives with G. stellata,' and 

 Bell suggests that it is probably identical with it. The 

 Mediterranean ' Gebios littoralis,' Risso, is a nearly allied 

 species, which ranges to the coast of Norway, and may 

 therefore be expected to occur in intermediate waters. The 

 name Gebia no doubt signifies ' life in the ground,' and 

 Upogebia ' subterranean life,' in allusion to the burrowing 

 habits which make specimens of the genus rare. The young 

 ones, however, may be taken pretty plentifully at the sur- 

 face, and Sars has in consequence been able to describe the 

 first larval stage or Zoea-form, the second or transition 

 from Zoea to Mysis stage, the third or Mysis-form, the last 

 larval stage, and the first post-larval stage of adolescence 

 (see Plate IX.) From these descriptions it will be seen, he 

 observes, that Gebia in some respects is very distinct from 

 Nephrops and Galocdris, two of the genuine Macrura which 

 he had previously been examining, as well as from all the 

 Carides, while in several points of development it ap- 

 proaches the Aiiomura. In the Carides as in Calocaris the 

 rule appears to be that the first larval stage or Zoea form 

 is characterised by the presence of three pairs of well- 

 developed swimming appendages, representing the exopods 



