British Orihatidse. By A. D. Michael. 231 



shield, of the dorsal parts of the cast skins from the earlier stages, 

 which, adhering closely to the back of the perfect creature, or the 

 nymphs, as the case may be, give it the appearance of being a 

 totally different shape from what it is; this is seen in Damseus 

 verticilUpes, Nothrus thelej^roctus, and others, and is admirably 

 shown in the nymph of Tegeocranus latus. 



Before closing these general observations, I should mention 

 habitat : Danneus geniculatus and D. clavipes, the genus Hoplo- 

 phora, and some others, live chiefly under bark, and more especially 

 in decaying wood ; some of the genus Orihata may be found on the 

 leaves of trees, but the greater number of the Orihatidse are more 

 or less sohtary, and live either in moss, preferring that growing 

 on the lower parts of trees, or under stones, but I have found 

 them most numerous upon some of the parasitic fungi which grow 

 out from the stems of trees in woods ; this is specially the case with 

 Tegeocranus, The moss must be damp but not wet ; I have found 

 but few when it was either very wet or very dry. 



Transformations. 



I consider that the most interesting work that I have done for 

 this paper in this department is in tracing the transformations and 

 life-history of Tegeocranus latus, the larva and nymph of which have 

 not, to my knowledge, been before observed, and are remarkable 

 creatures ; indeed, I fancy that those who look at the nymph and 

 perfect creature will agree with me that no more singular trans- 

 formation exists amongst the Acarina. 



The mode of watching transformations which I have adopted 

 has been much the same as I employed in breeding Cheyleti and 

 Glyciphagi; I have succeeded better with a simple glass ring cell 

 with a loose thin cover kept on by a clip, than with more elaborate 

 or more perfect apparatus ; into each cell a small piece of moss or 

 decayed wood was placed, having been first carefully examined 

 under the Microscope to see that it did not contain mites or ova, 

 then the mites to be studied were carefully picked in one by one, 

 only one sort being placed in a cell, and only a few specimens; 

 each cell was examined every day, and air and moisture given when 

 necessary. When I was fortunate enough to find a captive com- 

 mencing its transformation, the whole apparatus was transferred to 

 the stage of the Microscope and the change watched ; I have usually 

 kept some twenty-five to thirty of these breeding cages going 

 through the past summer, but have found great difficulty in 

 keeping some species, and have not succeeded in getting them to 

 lay eggs, although I have bred through from eggs and larvae which 

 I have found,* 



The escape of the larva from the egg I have watched in the 



* Since this paper has been lodged with the Society I have succeeded in the 

 case of Tegeocranus coriaceus. 



