DE. JOUNSTON Oil TUE ACABIDES OP BEBWICK8HJRB. 365 



are actually spinulose. The mite creeps with moderate quick- 

 ness and at a regular pace, the first pair of legs being kept 

 well forward and used as feelers, touching the ground with 

 short and un intermitting palpitations. 



When first I saw this mite there seemed to me no doubt of 

 its being the Trombidium fuligiuosum. The character of this 

 given by Latreille applies well to our species, but Koch's fi- 

 gure of it proves them to be distinct and very different. In 

 the true T. fuliginosum the sides do not appear to be sinuat- 

 ed ; and the eyes are supported on the branches of a common 

 pedicle which stands at the base of the rostrum. This is a very 

 essential distinction, — so much so that, in conjunction with 

 the contour of the front and structure of the mouth, it re- 

 moves the insect from the genus Trombidium, and places it 

 in Rhyncholophus. It possesses all the characters of this 

 genus as defined by Dugbs,* but differs from the few species 

 he describes, although nearly allied to his K cendr^. 



After the preceding remarks were written I had an oppor- 

 tunity of referring to Hermann's work, in which our species 

 is figured under the name of Trombidium murorum. The 

 figure is a good one, but the description is very defective. 

 Hermann says that it lives upon walls in troops. 



22. Dekmanyssus musculi. 



D. oblongus fulvus margine postico albido, dorso villoso, 

 vitta biflexa nigricante ad latera signato, setis crurum semi- 

 pectinatis. — Dermanyssus musculi, Koch Uebers. Arachnid, p. 

 81, tab. 9, fig. 46. 



Desc. Mite of a yellowish-brown colour marked on the 

 back with a dark vitta or line forming two sigmoid fie:rares 

 on each side in front : Body ovate-oblong, contracted at the 

 shoulders and hence narrowed forwards to an obtuse point 

 armed with two stout bristles ; the back plano-convex with 

 a narrow white membranous border, thickly covered with 

 very short appressed somewhat curved bristles or setae ; the 

 venter membranous with an elongated triangular sternal 

 plate sinuated near the middle and with its base towards the 

 anal pore, which is placed near the margin in a kidney-shaped 



• Yet being tartigrade, it differs greatly from oar Erythraos rapestris, as 

 also in the proportional length of the tegs to the body. 



