478 ON THE SPECIES UPOGEBIA STELLATA AND GEBIA DELTUEA. 



The hairs on the rostrum and carapace, and also on the edges of the 

 abdominal plates, are longer and thicker in dcUura than in stcllata, and 

 give it a more shaggy appearance. 



In small specimens, however, these differences are not so marked. 

 But stellata has one mark which always distinguishes it from dcltura, 

 namely, a small spine on the curved edge of the frontal margin of the 

 carapace behind the eye-stalks. In ordinary specimens it is easily 

 seen ; in very small ones a lens may be required to detect it, but 

 its presence in stellata is constant. In dcltura it is absent, and 

 the margin of the carapace forms an unbroken curve. The spine is 

 shown in the figure (c/. Figs. 1 and 2). 



This spine is not shown in the figures of either Leach or Bell. 

 It would hardly be visible on so small a scale ; also, it would hardly be 

 seen in the position in which the animal is drawn. From the above 

 considerations it appears that Upogebia stcllata and GcMa dcltura are 

 clearly distinct species. 



