320 ME. A. I). MICHAEL OX THE VARIATIONS IN THE 



Fig. 16. (Left lower corner.) Lcelaps (?) ligoniformis, sp. n. (page 316), $, dorsal aspect; x 75. 

 Mandibles almost entirely retracted. 



Pig. 17. (Near 16.) The same species ; chela of one of the mandibles of the male from the outer side ; 

 x 600. 



Fig. 18. Holotaspis montivagus (page 287) : distal portion of the epistome of the female; x 345. This 

 organ is hyaline; the smaller, central, Y-shaped projection not so much as the rest. The basal 

 part of the organ, which is not drawn, is simply a continuation of what is drawn, forming a 

 sub-triangular lamina with slightly rough edges. The wavy lines shown on the figure are 

 markings, not hairs. 



Fig. 19. (Middle of right edge.) Gamasus crassus, Kramer (page 296) : chela of one of the mandibles 

 of the male seen from the outer side ; x 190. The obovate foramen is seen in the movable 

 arm, and the extremely minute poison-fang and duct (?) in the fixed arm. 



Fig. 20. The same species: epistome of male, three-quarter view from above; x 190. It is placed in 

 this position in order to show how the distal end curves downward. The large central triangle 

 is hollow and contains fine cellular matter ; the peripheral part is dense chitin. 



Fig. 21. The same species : epistome of female seen from above; x 190. Wholly chitinized. 



Fig. 22. Expulsory vesicle from one side of Hamogamasus horridus (page 311) ; x 65. 



Fig. 23. Pharyngeal chitinous skeleton of Htemogamasus horridus (page 310), three-quarter view from 

 below ; x 170. The truncated (upper) end is the oral end ; the small piece of tube springing 

 from the lower (pointed) end is the commencement of the oesophagus. 



Fig. 24. Four ripe spermatocysts taken from the proximal end of the testis of a male Hcemogamasus 

 hirsutus immediately after dissection in water containing a small quantity of potassium 

 acetate; x 400. 



Fig. 25. Five spermatocysts taken from the sacculus fcemineus of the female of the same species 

 immediately after dissection in similar liquid ; same amplification. 



Plate XXXIII. 



Fig. 26. Four spermatocysts taken from the ripest found in the testis of an adult male Lcelapx acuta 



immediately after dissection ; x 150. 

 Fig. 27. Group of spermatocysts taken from the testis of an adult male Lcslaps vacua immediately after 



dissection ; x 300. The lowest are the ripest. 

 Fig. 28. Three spermatocysts taken from the cornu sacculi of a female of the same species immediately 



after dissection ; x 300. 

 Fig. 29. The whole genital system of an adult male Gamasus terribilis (page 290), x 55, showing 



the two testes joined by a thin central band, the azygous ductus ejaculatorius, and the great 



accessory gland. 

 Fig. 30. (Right middle.) The whole genital system of an adult male Lielaps cuneifer (page 292) ; 



x 70. The organs are in the natural position, as seen from above ; the testis transversely 



across the body. The testis and vasa defercnt.ia nearly hide the great accessory gland. 

 Fig. 31. (Left top corner.) The same system from the same species; x 150. The testis is turned over 



backward, and the vasa deferentia extended, so as to show the bifid distal end of the accessory 



gland. 

 Fig. 32. (Below fig. 30.) Terminal portion of the testis of the same species, x 300, showing the early 



condition of the sperm-mother-cells and their development iuto riper spermatocysts. The 



mature spermatocyst is very large in this species. 



