i68 



ARACHNOIDEA. 



CASE cannot be allowed. It is an extraordinary species of mite, which 



^^' was found on the posterior nares of the seal named Halichaerus 



gryphiis, in the Irish seas. Both larvae and perfect insects were 



found in abundance ; we give copies of the figures, which will 



save description. It is no doubt most interesting and most 



Halarachne halichoeri, larva. 

 Copied from AUman. 



Ditto, perfect insect. 

 About J of an inch in length. 



curious, but it is not an ocean mite, any more than the seal 

 on which it is found is a fish. It is merely a parasite on an 

 amphibious mammal, which spends much of its time in the sea. 

 Notwithstanding the name which he imposed upon it, Professor 

 Allman, whose acute discrimination of affinity is second to 

 none, at once referred it to its proper place. In fact, as soon 

 as he got possession of the young mites there was no room to 

 doubt — they are soft -bodied Gamasi (Seji), as plain as possible, 

 but the perfect mite would have been much more puzzling. 

 Guided by the light of the larvae, w^e see that it belongs to this 

 section of Gamasidae, although the elongate form of the perfect in- 

 sect suggests an approach to the Dermanyssi, and notably of one 

 nearly if not quite as long and narrow as itself, that is found in the 

 nostrils of the, common goat-sucker. It is curious to speculate on 

 the causes which led to the selection respectively by two species of 



