HYAS COARCTATUS. 



87 



Mr. Thompson, " from the North to the South of Ireland 

 this species prevails." This extensive range authorises me 

 to consider it as even more generally distributed on our 

 coasts than H. araneus. In the young state it is very 

 difficult to distinguish the two species, as the former has, 

 in its early age, the spreading form of the post-orbitar pro- 

 cesses which distinguishes the present species in its perfect 

 adult condition, and which is gradually lost by the other. 

 It is said by Mr. Hailstone to spawn in January. Amongst 

 those which I obtained at Sandgate in the month of May, 

 were several females, all without spawn. 



Mr. Hailstone described in the eighth volume of Lou- 

 don's Magazine of Natural History, what he considered to 

 be a distinct species, under the name of ffi/as serratus. 

 There can be no doubt that these were very young speci- 

 mens of the present species, as was suggested by Mr. 

 Westwood in some observations on Mr. Hailstone's com- 

 munication. There were three specimens, which Mr. H. 

 states v/ere all males ; but as the largest was only a quar- 

 ter of an inch long, it would be impossible at so early 

 a period to distinguish the male from the female by the 

 abdomen. 



