DESCRIPTIONS OF GENERA AND SPECIES. 217 



HISTIOSTOMA PULCHRUM,* Kramer. PL IV, figs. 410. 



Histiostoma pulchrum, 1886. Kramer, " Ueber Milben" (second 

 paper of that name), in ' Arch. Naturg.,' 

 52 Jahrg., Heft 1, p. 259, T. 12, fig. 18. 

 1897. Berlese, ' A. M. S. Crypt.,' p. 103. 

 ). Kramer, 'Thierreich,' Lief. 7, p. 134. 



1899. 



Length, both sexes 

 Typical length, both sexes 



breadth, both sexes . 



length of legs, first pair 

 second pair 



third paii- 

 fourth pair 



30 to '40 mm. 



*35 mm. 



17 



14 



17 



13 



16 



This well-marked and somewhat singular species was 

 first found by Dr. P. Kramer in 1886 ; I am not aware 

 of any record of its having been found again until the 

 present one. Kramer found the adult male and the 

 nymph and larva. The female and hypopus are, I 

 believe, now described for the first time. 



Colour yellowish white, or light buff, the opaque 

 white given by the excremental matter showing through 

 the dorsal cuticle is conspicuous, as in other species of 

 the genus. 



Texture dull, without polish. 



Male (fig. 4) has a tendency to a diamond shape, 

 but is truncated and rounded posteriorly ; the diamond 

 form is not nearly as well marked as in the d of H. 

 rostro-xerratum. The cephalothorax, including man- 

 dibles, is nearly as long as the abdomen ; the division 

 between the two is very conspicuous, and the body 

 is widest just behind it. Rostrum slightly bulbous 

 at the proximal end. Mandibles (PI. Ill, fig. 13) not 

 mentioned by Kramer in his original description, but 

 in ' Das Thierreich ' he states that they have numerous 

 saw-like teeth on their under edge. They certainly 

 have something of that nature, but I should scarcely 

 call them teeth. The whole mandible is very thin, and 

 is flexible, bending sideways when the leg presses 



* Pulcher, beautiful. 



