March 1, 1868.] 



HARDWICKE'S SCIENCE-GOSSIP. 



49 



FUKZE MITES. 



By the Rev. TF. W. SPICER, M.A. 



Through the 



kindness of a, 

 friend I have 

 been furnished 

 with a liberal 

 supply of the 

 curious, soci- 

 able, web-form- 

 ing mite, noticed at p. 124 of 

 last volume, as forming colo- 

 nies on the common furze 

 {Ulex Europeans). It would 

 appear from that notice, that 

 Dr. Milner Barry was the first 

 to draw the attention of the 

 scientific world to this little 

 Acarus, and that he transmit- 

 ted specimens to Mr. Meade, 

 the arachnologist, in 1S55. 

 The latter states, in his reply 

 to the doctor, that the animal and its cocoon are 

 both new to him, nor can he anywhere find a de- 

 scription of them. This account was read before 

 the Entomological Society that year ; and here, so 

 far as I am aware, the matter was allowed to rest ; 

 at least, I have not myself come across any further 

 communication on the subject. 



In the absence of information at the hands of 

 others, the following remarks may possibly be of 

 service to some of the readers of Science-Gossip. 

 After careful examination, I can see no reason to 

 separate the present species from the genus to which 

 it was assigned by Dr. Meade— Tetranychus of 

 Dufour. The mouth and the parts connected with 

 it are marked by the characteristics common to 

 that family; the palpi being remarkably stout, 

 pointed, aud longer than the labium. The pre- 

 vailing colour of the body is red, with longitudinal 

 bands of a darker shade traversing the sides. After 

 death by immersion in spirits of wine, which 

 destroys the red colour, these bands appear to re- 

 solve themselves into globular masses of some dark 

 substance in the interior ; at any rate, these masses 

 No. 39. 



appear for the first time after the true colouring 

 matter has been removed from the epiderm. On 

 the underside the body is of a uniform hue ; but, 

 strange to say, in addition to the red forms, there 

 are mingled with them numerous specimens in which 

 the abdomen is dark green, while the head, thorax, 

 and legs are of a lively pink. Whether these are 

 young ones or males (for they are much smaller than 

 the red ones), I am unable to say. Walckenaer, in 

 describing an allied species, Tetranychus pninicolor , 

 in which there is a similar variation of colour 

 among individuals, simply speaks of the green ones 

 as "the little ones" (les petits). One thing is 

 certain, that the green-coated specimens are all 

 furnished with eight legs, and consequently cannot 

 be very infantine ; since it is universally allowed 

 that immature forms among the Acarina are invari- 

 ably six-legged. The eyes, which are in every case 

 two on each border of the thorax, are prominent 

 and conspicuous ; being a very dark red in the red 

 specimens, and a bright red in the green— shining 

 out in these latter with the same intensity and dis- 

 tinctness which characterizes the eye-spots ii; 

 Englena viridis and similar infusoria. 



In shape, the body is long, with a tendency tu 

 oval ; more so in the green than in the red speci- 

 mens. In the former, too, the sides form an 

 uninterrupted line from the thorax to the extremity ; 

 whereas those of the latter have two or three 

 deep indentations, corresponding to the abdominal 

 segments. The dorsal surface is marked (as in 

 most of the Trombididae) with very fine transverse 

 lines ; and is divided into four segments, of which 

 the thoracic is unusually large. They are very 

 distinct in the red, less so in the green individuals. 

 The body generally is covered with stiff white hairs, 

 or spines scattered over its surface (but not so 

 plentiful as in many Acari), and mostly directed 

 backwards; while those on the eight legs, where 

 they are far more abundant, all have a forward 

 direction ; the end ones becoming slightly curved. 

 The legs are rather slender, marked, like the back s 

 with very fine lines, and divided into seven joints, 



c 



