38G Transactions of the Society. 



carrying on their backs the notogastral (dorso-abdominal) portions 

 of all their cast skins, which form concentric rings upon the back 

 of tlie existing creature. The nymphs of. Tegeocranus latus, 

 Leiosoma [Cepheus) jjcilmicinctum, and Cepheus ocellatus have been 

 especially noticed as very remarkable creatures, and the present 

 species is not inferior to them in interest and singularity. It is 

 distinctly constructed upon tlie type of the nymph of Tegeocranus 

 latus ; it may be remembered that this nymph, which may fairly 

 be considered a typical form, has the abdomen, and each cast 

 abdominal skin, bordered by a series of large, brown, trifid pro- 

 jections, from the central cusp of each of which springs a great 

 serrated spine of clear chitin, doubly curved, so as to form almost 

 a line-of-beauty, directed more or less backward. In the present 

 species the trifid projection is absent, or rather the central cusp 

 alone remains, forming a very large projecting paj^illa, of which 

 there is a series all round each skin ; from each of these springs a 

 spine somewhat of the nature of those borne by T. latus but twice 

 or three times as long, far thinner and finer, and with the serrations 

 much further apart, so that it gives the idea that if a spine of 

 T. latus were ductile, and could be drawn out to extreme length 

 and tenuity, it would then resemble one of those of Cepheus 

 hijidatus. The spines radiate much more than those of T. latus, 

 and have the peculiarity, that, while those on the anterior parts of 

 the body are stiff, those bordering the posterior part are more or 

 less flexible. The remarkable length of these spines, their elegant 

 shapes, and the complicated pattern resulting from the curving and 

 crossing of those projecting over the cephalothorax, render the 

 animal as singular a creature as can readily be found. 



The mode in which it has been discovered gives it an additional 

 interest in my eyes, as one always has a special liking for what 

 has only been attained by considerable care and trouble. Cepheus 

 hijidatus is a rare species, very diSicult to obtain ; I have not ever 

 found the nymph or larva, and I have traced it solely from the 

 system of preserving the creatures alive in glass cells, and en- 

 deavouring to breed from them, which I have adopted in most of 

 my researches on the life-histories of Acarina. Last autumn at 

 Keswick (Cumberland) I came across three or four living adult 

 specimens of the species, and I determined to endeavour to get 

 them to lay eggs and rear them. I carefully isolated them in a cell 

 without other creatures of any sort, and placed them under such 

 hygrometric and food conditions as experience told me would be 

 most likely to keep them in health ; after a few weeks I was pleased 

 to find four young larvae, just hatched, and of a kind new to me, 

 but evidently one of the Oribatidae ; one of these is figured at plate 

 YII. fig. 1. I carefully reared these larvse until they attained the 

 nymphal stage, and through all the ecdyses of that stage, the whole 



