MARINE MITES. 211 



CASS land, York, and Firth of Clyde, and, therefore, probably all round 



XIII 



England and Scotland. 



Halacarus notops {Gosse) (Pachygnathus notops, Gosse ; Pachygnathus 

 seahami, Hodge; and Pachygnathus minutus, Hod^e, larval form). — 

 5. Magnified sketch of ditto, copied from Gosse's figure. 



The body is flat, lozenge-shaped, hyaline and colourless at the 

 margins, but the interior is almost filled with flesh of a deep blue- 

 black hue, perfectly opaque, and of a defined sinuous outline. In 

 the centre of the back, just behind the head, is a bright ruby-like 

 round eye placed in front of the opacity and between the first legs. 



Taken by Mr. Gosse, at Ilfracombe, and by Mr. Norman abun- 

 dantly on weeds in rock pools, Balla Sound, Shetland. 



The reader may have observed, 

 that in speaking of those eyes on 

 the back of some of the preceding 

 species, near the origin of the second 

 pair of legs, we have called them 

 eyes or supposed eyes ; we did so, 

 because we remembered that in 

 the Oribatidae (the next section of 

 mites), there is an organ placed very 

 much in the same position, which 

 for long was supposed to be their 

 eyes, but which, when its true nature 

 was ascertained, turned out to be not eyes, but breathing pores. 

 We do not say that it is so in the Halacarida^, but as it may be 

 so, we thought it as well to qualify the term with a point of 

 doubt. 



Halacarus notops. Copied from Gosse's figurcc 



Family ORIBATID.^, or BEETLE MITES. 



The Oribatid?e are mites which have a hard chitonous integu- 

 ment like that, of a beetle, and they are generally brown or black. 

 globula.r, and shining. In their young state, some of them (Hoplo- 



