SNOUTED MITES. 143 



CASE Statement of such diversity, accompanied with no corresponding 

 differences of other structure, would seem to show that in this 

 group the presence, absence, or number of eyes was not a matter 

 of generic importance ; and as we go along we shall see other 

 instances of the same thing in other famiHes of mites and insects. 

 There are many species of insects found in the deep and 

 obscure recesses of limestone caverns, or other dark places, which 

 have no eyes. The spot where the eyes should be is smooth, and 

 to the naked eye identical with the neighbouring surface, but some 

 of them beyond doubt belong to well-known and unmistakeable 

 genera which have eyes. These organs would appear, therefore, 

 not to be entitled to rank among the structural organs which dis- 

 tinguish important divisions of living beings. 



Genus Molgus ? {Dujard). 

 Mouth or quasi-head without a constriction or neck behind it. 



No. I. Molgus longicornis {Linn.), (Ac. 

 Basteri, Johnston), Acarides of Ber- 

 wickshire, in History of Berwick, 

 Nat. Club, ii. 227.).—!. Magnified 

 sketch of ditto. 



As already said this probably 

 belongs to Dujardin's genus Mol- 

 gus. It occurs in Berwickshire, 

 in Northumberland, and other 

 parts of England, where it is „ ,^ ^ ,, , , . . „ . ^c ^ 



*■ *-" ' Mouth of Molgus longicornis. Copied from Dr. 



common on the sea-shore during johnston-s figure. 



the summer months, running quickly about among stones above 



high-water mark. 



It is scarlet, with the body blood red, and as if divided into 

 several large sub quadrangular compartments, formed apparently 

 by a thickening of the skin, pear-shaped, about an eighth of an 

 inch in length : in fact very like the small weevil called Apion ir 

 shape and size. 



