IlALiiKiM' — The Acarina of the Seashore. 127 



ill a continuous test, with the exception of the sternal and pedal lej^ions. 

 Sternum absent (though present in tlie nyviphu cokojArata st-d<^c) . Endopodial 

 and metapodial plates well developed. Ambulacra on all ijaiis of legs. 

 lype Tliinoseius Berledi sp. no v. 



Thinoseius Beiiesii sp. nov. (I'l. XXII, lig. 9 a, e.) 



Female (fig. 9 a, b) : Length aljout 760/( ; Ineadtb, 540//, in the Malahide 

 specimens (a Swanage specimen measures 845/^ x 590//). Colour during 

 life, light brown, with a conspicuous darker spot on each side- of the dorsum. 

 Shape, broail and pyriform, end margin sometimes flattened. Epidermis very 

 minutely shagreened, also marked towards margins with waved lines, and 

 there are traces of a polygonal network on the dorsal surface. Hairs short 

 and sparse. Sternum and jugular plates absent, the sternal region being 

 very weakly chitinized ; four pairs of hairs present. Tritosternum normal. 

 Endopodial plates well developed, usually with sharp processes, as in the 

 genus -Halolaelaps ; metapodial plate, a thin chitinous band, bounding the 

 basal segment of the fourth leg. Peritreuie sinuate, enclosed with and 

 bordering tl:e ventral plate. Genital plate of the usual trapezoidal form, 

 slightly longer than broad ; anal plate fused in the chitinized cuticle of the 

 ventral region. The front margin of the last is sinuate, and placed near it is 

 a pair of small ring-like structures embedded in the cuticle. 



Capitulum, with a short and broad maxillary plate, rounded behind, with 

 t^ree pairs of moderately long hairs ; ma.xillary lobes normal. Epistomal 

 margin semicircular, armed with five or six long and stout spines, which 

 are branched at their extremities. Chelicerae (fig. 9 c) very small. Palps 

 robust (length, about 180/t); second segment with three short dorsal spines ; 

 inner and outer margins with one fine hair. Legs of moderate length, 

 robust; hair armature weak ; tarsi not attenuated, all pairs witli ambulacra. 

 The last (fig. 9 d) carry a pair of bristle-like lateral lobes resembling tliose of 

 the genus Episeius. Male unknown. 



Nymplm cokoptratu (fig. 9c). — Length, about 500/< ; breadth, oOO/i. 

 Shape, less strongly pyriform than in the adult ; side and end margins 

 flattened ; hair armature relatively stronger. Epidermis minutely punctured 

 and reticulate. Sternal shield of the usual V-shape ; front margin strongly 

 convex. Anal plate small and heart-shaped. Peritreme long and curved 

 inwards; inner margin serrated near the extremity. A pair of small lunate 

 inguinal plates are present. 



The most interesting characteristic of this new genus is the abs<'nee of a 

 sternal shield, a very rare feature in the Gamasoidoa. Lorlese has described 



