308 THE ENTOMOLOGIST. 



variety of the former. My opinion has heen formed, both from 

 the study of the imagines in tlieir various phases of variation, 

 and the natural conditions of their occurrence. In the absence, 

 however, of any actual proof of their distinctness, I have 

 treated the form that I consider distinct as a local race or variety 

 of nictitans under the name of paludis in the following notes on 

 the species. 



With regard to the superficial differences between nictitans and 

 paludis I have made the following notes : — Paludis is generally 

 larger than nictitans, and in its different phases of variation is 

 rarely, if ever, of the red coloration which is common in some shade 

 or other to all the varieties of nictitans. The reniform of imludis is 

 always more narrow, owing to the absence of the outside line on 

 the inner edge of the reniform, which is present in that oi nictitans; 

 it is also less strongly marked, and always white or orange, never 

 red. The posterior wings of paludis are more ample and more 

 rounded on the hind margin, the anterior wings less arched on 

 the costa. The typical colour oi paludis is ochreous or ochreous- 

 grey, and its variations in ground colour assume a greenish tint, 

 until its extremes may be described as greenish grey ; the typical 

 colour of nictitans is red, and its extremes are reddish brown or 

 black. Both are reticulated with faint transverse lines, but 

 nictitans is generally more strongly marked in this respect than 

 paludis ; the faint transverse line parallel to the hind margin of 

 the anterior wings is of a different shape in paludis to that of 

 nictitans, being more completely hollowed just below its centre. 



With regard to the occurrence of these forms in a state 

 of nature, the following facts are very striking : — On the 

 marshes around Rochester, bordering the Medway, paludis in all 

 its form of variation occurs. In the woods around Rochester, 

 not a paludis is to be found ; all are nictitans. At Sligo Mr. 

 Percy Russ takes nothing* but paludis, some of which are 

 exceedingly beautiful forms. Mr. Harrison, of Barnsley, has sent 

 me for inspection the pick of the Yorkshire forms, — all are 

 nictitans, there is no sign of paludis. In London nictitans is 

 often common, but I have never seen paludis. At Shoeburyness 

 most are paludis, whilst at Deal both forms occur. I have taken, 



* I must modify this statement, as Mr. Russ last month (Oct., 1888) sent me a 

 very strongly-marked specimen of H. nictitans, var. erythrostigma, with a query as to 

 its being nictitans at all, the form, with a red ground colour, being entirely new to 

 him. 



