Vol. Xxix] ENTOMOLOGICAL NEWS 337 



other hand, longer than broad. They bear a stout lunar grasping 

 spine, a single elliptic spine on the outer side and three slightly smaller 

 spines on the inner side. There are no bristles on tarsi III and IV. 

 The tactile bristle of segments III and IV is small and inconspicuous. 

 The tibia bears no spine in appendages III and IV of the female or in 

 appendage IV of the male. Genuals III and IV of the female bear a 

 single small bristle pointed outward. The third appendage of the male 

 is heteromorphic (Fig. 6). The tarsus is practically reduced to a very 

 large median hastate spine and a pair of smaller auxiliary spines. The 

 tibia of male appendage III bears a small tactile bristle and a short 

 broad spine. 



The palpus of the prehypopid nymph is slender and its tarsus is 

 crowned with several small bristles (Fig. 8). This appendage changes 

 in the adult mite, so that it is shortened and broadened, while the 

 tarsus is bluntly triangular and heavily chitinized (Fig. 9). As in 

 other Tyroglyphidae, the mandibles are chelate without any marked 

 dentitions. 



The gravid female has from one to four large eggs, measuring about 

 170 by 90 /j.. The shell of the egg is moderately thick (Fig. 5). The 

 contents of the egg consist of large, highly refractive granules, irreg- 

 ularly oval in contour. The vulva is situated far cephalad between 

 appendages III and IV. Around it is a broad horse-shoe shaped chiti- 

 nous band, distinctly crenate anterior to the vulva. On this band are 

 two pairs of genital suckers. The anus in the female is anterior to 

 the ventral bristles. 



The male is characterized also by the genital suckers. In addition 

 the copulatory suckers, entirely postanal, are conspicuous. They have 

 a large central cavity (Fig. 7). Only heteromorphic males have been 

 found. 



Type specimens are in the collection of the writer, Nos. 18. i 

 and 18.2. 



Immature Stages. There is a distinct hypopus. The prehypopid 

 stage is a delicate creamy yellow octopod, whereas the hypopus has a 

 heavy brownish yellow chitinous covering. The hypopus measures 0.26 

 mm. long by 0.16 mm. wide. The cephalothorax and abdomen are 

 approximately equal. They are separated ventrally by a transverse 

 suture. Appendages I and II are considerably larger than III and IV. 

 Tarsi I and II are acute, ending in a spine. The round sucking plate 

 at the posterior part of the ventrum consists of two inner rows of three 

 suckers each and two outer rows of one sucker each. In addition, 

 there is a pair of suckers anterior to the plate. 



The relation of R. sac/it tatac to R. Ji\acintlii and R. rhizo- 

 phagus is shown in the following table: 



