416 MR. A. D. MICHAEL ON [June 3, 



Europe. There are onlj- 102 known British species of Ori- 

 batidiB, and it is perhaps rather remarkable that I should have 

 found a quarter of them in a two-months' tour in Algeria. 



Of the new species probably the most remarkable is the curious 

 new Caculus before referred to ; not only because there was only 

 one species of this very exceptional genus known previously, but 

 also on account of its size and the singular arrangement of the hairs 

 on the cephalothorax. There are, however, other creatures of con- 

 siderable interest. One of these I propose calling Notaspis hur- 

 rowsii ; it is rather a handsome Acarid, but is quite typical of the 

 genus, and is just such a species as one might expect to find in 

 England : it has not, however, been captured anywhere in Europe 

 so far as I know. What really makes it noticeable is the example 

 it affords of the very wide distribution of these minute creatures, a 

 fact which I have called attention to more than once. The species 

 is, I believe, unrecorded, but just before I left for Algeria the Rev. 

 C. R. N. Burrows sent me a small collection of Oribatidas which he 

 had lately formed in the neighbourhood of Lake Winnipeg in Canada. 

 He remarked that the species seemed mostly identical with the 

 British, which proved to be the case, but amongst them were a few 

 unrecorded, the most conspicuous of which was the present species, 

 which I at once recognized when I found it in Algeria, where it is 

 not uncommon. I cannot detect any difference between the African 

 and the Canadian specimens. Another very curious creature is that 

 which I propose to call Damceus phalanciioides. The various 

 species of this genus have mostly long and slender legs, as compared 

 with other Oribatida3, but in the jjresent species this character is ex- 

 aggerated to such an extent that it would hardly have been supposed 

 that they could remain unbroken when the extreme brittleness of 

 the chitin in this family of Acarina is remembered. Another new 

 species of the same genus is exceptional, viz., that called Z), patel- 

 loides. Almost all the members of the genus have a more or less 

 globular abdomen, or else one which is discoidal, the latter being 

 considered a separate genus by some Acarologists. In the present 

 species the abdomen is pyramidal, a form which I do not think is 

 found again in any known member of the family ; in order to 

 appreciate this shape the creature must be seen sideways, I have 

 therefore drawn it in that position. 



An Acarid which is not, I think, new, is nevertheless interesting 

 on account of a difference between the Algerian specimens and those 

 hitherto recorded in Europe. With the single exception about to 

 be mentioned, all known Oribatidse have either monodactyle or 

 tridactyle claws. Among the tridaetyle claws some are homodaetj'le, 

 i. e. have the three claws similar ; others are heterodactyle, i. e. 

 have the central claw different from the lateral pair ; usually the 

 central is much the stronger, the lateral claws being thin and weak. 

 It was formerly thought that Oribatidas could be classified chiefly 

 by these differences of the claws, but wider knowledge has shown 

 that any such classification would be extremely artificial. There is 

 an English and European species called Nothrus sylvestris, which is 



