tURTHER NOTES ON ACARI. 113 



This species was found by Mr. A. R, Spoof in spawn of Lymnaea 

 in subsaline water, 26 July 1896. (fig. 6 — ^16). 

 Length 0,760 millimeters. 



The dorsal surface of the céphalothorax shows dark-coloured ridges, 

 which are better figured (fig. 6) than described. There are two 

 lamellar hairs or bristles and two rostral hairs. The skin is smooth. 

 No pseudosticmatic organs nor pseudostigmata are discernible. 

 The dorsal surface of the abdomen is convex, sculptured as 

 shows us fig. 7. As far as the opake animal permitted to discern, 

 the short bristles, in toto 48 in number, stood in longitudinal and 

 curved transversal rows, as fig. 6 shows us. The colour of the 

 céphalothorax and a quadrangular area of the abdomen is brown, 

 the abdomen itself darker brown , and its margins nearly black. 



The claws (fig. 9 and 40) are tridactyle and very heterodactyle, 

 the central claw being almost twice thicker than I he lateral ones. 

 Moreover the larsus bears four thick hairs hooked at their end , so 

 that each tarsus actually ends into seven hooks , which may be very 

 useful to the animal in crawling on the slippery submerged stems 

 of aquatic plants, for else I cannot explain the presence of these claws 

 and crooked hairs. I believe that the occurrence of these mites in 

 the spawn of Lymnaea is accidental; they feed on vegetables. 



The ventral surface (fig. 8) scarcely shows demarcations of the 

 epimera, or a division of the sternum by apodemata. The genital 

 covers form together a square ; and each of them bears on its free 

 margin four minute hairs. The anal covers form together a tra- 

 pezium ; each of them bears, as for as I could discern , only one 

 minute hair near the free border, or anal split. The ventral surface 

 is smooth and dark brown coloured , the margins being almost black. 

 The legs have only a few bristles , except their tarsus , which is 

 described above. 



The nymph. Length 0,795 millimeters. 



The nymph has a leathery skin like the species of the genus 



Camisia. The dorsal surface (fig. 44) shows us a céphalothorax 



with representatives of the lamellae , being here only tickened ridges 



of the skin. There are two short curved lamellar hairs and two 



Tijdschr. V. Entom. XLIIl. 8 



