404 H. E. EWING. 



Fam. TETRANYCHIDyE. 



Palpi free ; tarsi never ending in suckers ; body with a 

 division between cephalothorax and abdomen. Last seg- 

 ment of palpus ending in a thumb ; skin without shields ; 

 coxse of legs arranged more or less into two groups ; hairs 

 on the body usually arranged into four longitudinal rows. 

 Many of the members of this family spin threads, hence they 

 are called the " spinning mites." 



Geu. KAPHIGINATHUS Duges. 



No projecting tubercles from the anterior margin of the 

 cephalothorax ; body subglobose ; hairs of the body arranged 

 in four longitudinal rows. Legs moderately short. The 

 skin of the dorsal surface is tessellated by having many small 

 thickened, elevated areas. 



Representatives of this genus are very common in Europe. 

 The following species is the first of the genus to be recorded 

 from America. 



Raphignatlms tessellatus n. sp. 

 (Plate XIII., Figs. 5, 6.) 



Red ; body completely covered with small, darker, areas arranged 

 like mosaic work. These areas are all of about the same size but are 

 very irregular in shape ; between them is a network of light yellowish 

 red integument. Legs graulate. 



Cephalothorax composing one-half of the body and similar to the 

 abdomen in shape; anterior margin oval. A single pair of eyes is 

 present near the side of the cephalothorax, between legs one and two. 

 The cephalothorax bears four pairs of stout, stiff, slightly clavate 

 bristles arranged around the outer margin. Mandibles less than one- 

 half as long as the palpi ; second segment of palpus three-fifths as 

 broad as long, broader at the proximal than at the distal end ; third 

 segment as broad as long ; fourth segment half as long again as third 

 segment and ending in a stout, slightly curved claw ; thumb short, 

 cylindrical, two-thirds as broad as long and not extending to the tip 

 of the palpal claw. Palpi apparently hairless from below ; above, seg- 

 ment two bears one large, slightly curved and slightly pectinate 

 bristle ; segment three has a very long bristle near its middle ; seg- 

 ment four with at least three bristles ; thumb with several bristles. 



Abdomen similar in shape to cephalothorax, excepting the middle 

 part of the posterior margin, which is almost straight. Abdomen 

 bearing seven pairs of stout, stiff, slightly clavate bristles; two inner 



