80 J. K. KiNAHAN on the Britannic Species of 



with minute blackish dots and star-shaped patches of reddish-brown, pale red- 

 dish-brown in stripes, pale blue, deepening into bright azure-blue on the abdo- 

 men, before the spawn is extruded, patches of opaque white, — all combine, 

 along with the varied tracery of its sculpturing, to render this one of the most 

 lovely of its family. 



Length, from 0'7 inch to 1-25 inch. 



Habitat, sandy gravel, and, though rarely, sludgy sand, in from five to 

 twenty-five fathoms. 



Habits active, swimming freely in the aquarium. 



Localities, Belfast, off the Gobbins ; Dublin, in deeper waters, very com- 

 mon in suitable grounds ; Galway, Isles of Arran, rare (^Prof. Melville). 



In ova in March ; ova salmon-red. 



This species, first established by Professor Bell, is very common about 

 Dublin, especially on the oyster and scallop (Pecten opercularis) beds. 



If due regard be paid to the characters of the rostrum and abdomen, it 

 cannot be confounded with any other British species, and from the foreign 

 species it may also be easily distinguished. 



From Mg. carinicauda (vide p. 48, supra), by the denticulations on the 

 carinas of the carapace, &c. 



From yEgeon cataphractus* it differs in the lesser amount of emargination 



• Mgeon cataphractus (Olivi), iEgeon loricatus (Risso). Milne Edwards has looked on this 

 species as identical with the male of Pontophilus spinosus (Leach), why, I know not. Exami- 

 nation of a male specimen thus marked in the British Museum (presented by Marquis Spinola, 

 from the Mediterranean), and of female specimens in the same collection marked as from the Me- 

 diterranean, and of female specimens in the Jardin des Plantes, furnish the following characters, 

 which also agree with Eisso's descriptions and imperfect figure. — VideN.R. del'Eur.,mer.5,p.58, 

 pi. 1 , fig. 3. 



Rostrum deeply emarginate; carapace armed with numerous strongly- toothed carinas terminat- 

 ing in teeth, which in the females project over the orbits. The abdominal segments in male — 

 first, with several distinct, but not continuous lines of teeth; second, a single median tooth; 

 third and fourth carinated and sculptured; fifth bicarinated (the carina; divergent) and sculp- 

 tured; sixth bicarinated; telson, as in Crangon, sulcate. Females — first, bicariuate and coarsely 

 sculptured; second, third, and fourth, carinated and highly sculptured; fifth and sixth, bicari- 

 nated and sculptured; telson deeply sulcate. The carina; in the female are all more strongly 

 marked than in the male, being mostly denticulate on their margins. The sexes may belong to 

 different species, but their differences are only in degree, and the female specimens are much larger 

 than the male. 



