1 6 REV. J. E. HULL ON 



1. Tarsus i much thicker than tibia i... ... brevimanum. 



Tarsus i not thicker than the tibia ... 2 



2. Dorsal trichomes all ahke ... ... ... scharlatinum. 



i.'^nterior and posterior trichomes dissimilar holosericeum. 



2. Sericothrombium holosericeum, L. 66, 67, 68. 



Tarsi i slightly clavate. Dorsal trichomes truncate- 

 clavate, but attenuate or even acute in the thoracic 

 region. 



The common " scarlet mite," abundant everywhere. 

 It sometimes reaches a length of 4mm. 



3. Sericothrombium scharlatinum, Berl. 67. 



Dorsal trichomes uniform — very slightly clavate with 

 rounded tips; about 130 /u. in length. Very 

 plentiful in West Allendale in May ; elsewhere 

 the records are hopelessly confounded with the 

 preceding. 



Yorkshire. 



4. Sericothrombium brevimanum, Berl. 66, 67. 



Trombidium miishami, Geo. 



T. bticcinator, Geo. 



Dorsal trichomes much shorter than in the two pre- 

 ceding species, varying a little in form, but all 

 truncate-clavate with expanded tips. 



Yorkshire. 



ENEMOTHROMBIUM, Berl., 1910. 



Dorsal trichomes more or less inflated (usually also 

 transversely septate) rising from a socket which 

 is generally rayed or lobed at its summit : the 

 trichomes of the limbs (at least of the upperside) 

 spatulate and feathered, plano-convex. Article iv. 

 of the palp with secondary claw or claws and 

 seriate spines. Eyes not pedunculate but seated 

 on a tuber. 



Type : lufoliosiivi, Can. 



