93 



LINCOLNSHIRE FRESHWATER MITES. 



G. F. GEORGE, M.R.C.S. 



The following' are some notes on observations of the g"rovvth and 

 changes of the appendage of a species of Megalurus extending 

 over a period of about six weeks. 



On Tuesday, August 29th last, I found in water taken from 

 one of my usual collecting ponds the day before, a male 

 Arrheniinis unlike any I had before noticed. Its general colour 

 was pale reddish with a yellow Y-shaped malpigian centre, the 

 legs a pale transparent blue colour, the fourth segment of the 

 hind leg spurred, the hair on the end of the spur curly, eyes a 

 bright Vermillion, the chain-like chitin coat very distinct, and the 

 lined condition of the epidermis which covered it was easy to 

 make out ; the striated epidermis I have before observed to be 

 most frequently and best seen in 3'oung mites which have 

 recently changed their skin. The most remarkable thing about 



Fig. I. Fig. 2. Fig. 3. Fig. 4. 



the mite was the tail, which was short and globular. At the 

 extreme end, in the centre, a small papilla, and another on each 

 side near the outer edge (see fig. i). On the yth of September 

 following the tail had slightly elongated and become conical 

 (fig. 2), reminding one of Piersig's figure of Arrheniinis com'ciis, 

 the central malpigian body extended almost to the end of the 

 tail, the side coeca were a semi-transparent warm brown colour, 

 and the end of the tail a rather transparent delicate pale pink. 

 On the nth this had become more elongated, and continued 

 semi-transparent, the end nearly square across, with the little 

 papilla in the centre, and above this some slightly blue chitin 

 plates. The mite now appeared to be very like the mite 

 described by me as Arrhenurus mantonensis (see figure in 

 ' The Naturalist ' for June 1903, p. 216). As development was 

 perhaps not yet finished, I still kept the mite alive for observa- 

 tion ; a week afterwards great changes had taken place in the 

 tail, two side projections had formed at the end, the chitin 



igo6 March i. 



