INTEENAL ANATOMY OF THE GAMASIN^.. 319 



galese of the same writer. Bcliind the oral tube is seen the bipilate organ (" Baiichtiister " of 

 Kramer, " labium " of Winkler, &c. j ; behind this, in the median line, the almost hexagonal 

 sternal plate ; then the genital plate with a membranous anterior edge, and a small crescentic 

 metapodie plate on eaeh side of it posteriorly ; finally, the anal plate (inversely pyriform) . 

 The stigmal jjlates are along the edges of the anterior part of the body. 



Fig. 3. The same speeies : last two joints of one of the mandibles of the male seen from the outer side ; 

 X 350. The lowest lobe and the two smaller globular lobes of the movable arm of the ehela 

 are less ehitinized than the other portions. The working or cardinal portion of the movable 

 arm is sunk in the fixed arm, and is only shown, as though the latter were transparent, in 

 order to exhibit its unusual I'orm and elliptical foramen. 



Fig. 4. The same species : eheki of one of the mandibles of the female seen from the outer side ; x 3.")0. 

 The two lamiuse on the under-edge of each arm of the chela are less ehitinized than the rest of 

 the organ. The fixed arm of the ehela in all Gamasid-mandibles is the upper arm. 



Fig. 5. (Near right lower corner.) The same speeies : epistome of the male seen from above ; x •iM. It 

 is very hyaline, but the basal triangle is rather more ehitinized than the remainder. The 

 radiating lines springing from this are markings, not hairs. 



Fig. 6. Hceiiioyumasus nuli, sp. n. (page 314) : chela of one of the mandil)lcs of the male fi'om the outer 

 side ; x 380. 



Fig. 7. The same sijecies : epistome seen from above ; x 350. It is veiy hyaline; the radiating lines 

 near the centre are markings, not hairs. 



Fig. 8. Hceiiwffamusus hirsuius, ?, dorsal aspect ; x 15. This drawing is to show the course of the 

 alimentary canal and Malpighian vessels; it is taken from a young, but mature, living specimen, 

 the internal organs showing through the dorsal surface in consequence of the transparency of 

 the cuticle. The spines and hairs are omitted for the sake of clearness ; the legs also are 

 omitted. The oral tube (rostrum) is in outline; the epistome is seen between and above the 

 extruded mandibles ; the irregular-sluqiedl plate of thin chitin on the dorsal surface is semi- 

 transparent, and varies in form in every specimen. The small vcntriculns, with its great 

 anterior and upper posterior c;eca, is dark (as in nature when the creature is recently fed) ; 

 the Malpighiau vessels arc almost white (as in nature when 'seen by reflected light). The 

 cloaca is shown, looking globular near the centre of the posterior end, between the distal 

 terminations of the cfeca. The striated part is the soft cuticle. 



Fig. 9. (Near centre of lower part of Plate.) The same sjieeies ; chela of one of the mandibles of the 

 male from the outer side ; x 650. The lobate proximal portion of the fixed arm is fiat fa 

 blade) and is very hyaline. 



Fig. 10. The same sjjccies : epistome of female seen from above ; x 350. 



Fig. 11. The same sjiccies : epistome of another female seen from the same direction and magnified to 

 the same extent, in order to show the variation in different specimens. Both this and fig. 10 

 are carefully made from actual examples. 



Fig. 12. Lalaps orihatoides , sp. n. (page 315), ?, dorsal aspect; x 65. The two conspicuous black 

 spots arise from the excretory organs showing through the cuticle. The nunuhbles are 

 retracted. 



Fig. 13. The same species: chela of one of the mandibles of the male seen from tlic outer side; 

 X 355. The sharp spine on the fixed arm of the chela is probably a poison-fang. 



Fig. 14. The same species: ehela of one of the mandibles of the female seen from the outer side; 

 X 300. 



Fig. 15. The same species: epistome of female seen from aijove ; x 300. The organ is very iiyaliue, 

 but the sub-triangular space at the base is rather more ehitinized than the rest. The lines 

 running forward from it are markings, not hairs. 



