British Oribatidte. By A. D. Michael. 195 



more convex as the creature gets older ; the diamond more angular 

 when young; its points become rounded off when the nymph ia 

 older. The abdomen has two dark red spots on its anterior margin, 

 and a rather white space between them ; the spots are joined by a 

 red line. There is a band of six black hairs pointing backward 

 about a fifth of the distance behind the anterior margin ; a little 

 behind this is a transverse mark, like a scratch on the skin, pro- 

 bably where some part of a cast skin has been attached ; posterior 

 to this is a somewhat flask-shaped patch, the largest part being 

 anterior and the smaller extending to the anal margin ; this patch 

 is doubtless a portion of a cast skin ; it is strongly dotted. In 

 the constriction answering to the commencement of the neck in the 

 flask are two large crimson spots, which seem to be subglobular 

 organs showing through the skin ; in the centre of each of these 

 is a small black ring, which seems to surround a minute opening ; 

 a separate patch of cast skin covers each spot ; the extreme trans- 

 parency of the integument and the colour of the internal parts 

 allow every motion of the latter to be distinctly seen ; whilst the 

 creature is active, the cells of the probably adipose tissue under- 

 lying the skin are plainly visible, the pigment lying round what 

 may be called the cell-wall, without entering on the question 

 whether it be a true cell. During the inert stage these cells seem 

 to break up. They are no longer visible, and the pigment is 

 mixed vaguely in the substance of the creature. 



NoTASPis BiPiLis. Herm. 

 Nymph, PI. V. Fig. 3. 

 Taken from inert specimen. 



This nymph is figured and described by Koch as a separate 

 species under the name of Murcia acuminata, fasc. 31, pl. 24. 



Average length about • 80 mm. 



„ greatest breadth „ ' 45 „ 



„ length of first pair of legs .. „ "50 „ 

 „ „ „ second and third ditto „ '30 „ 



„ „ ,, fourth ditto .. .. „ "40 „ 



Wliole creature flask-shaped. 



Colour clear white, very transparent, polislicd, but dotted all over 

 with fine punctures, internal parts showing through and producing 

 two dark brown spots a little behind the anterior margin of the 

 abdomen, joined by a lighter brown band, which is extended pos- 

 teriorly into a somewhat saddlc-shapcd marking, often found in 

 Acarina, and said l)y Claparcdo to bo the liver and excretory 

 organs. Rostrum in front of the stigmata, about one-fourth of whole 

 length, conical, with curved sides ; thence the ccphalothorax widens 

 rapidly and is excavated for the insertion of the two anterior 

 pairs of legs. Stigmatic hairs longish, filiform, and rather thick. 



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