

COMPAEATIVE MOEPHOLOGY OF THE GALEODID.^. 413 



centres in a Pseudoscorpion ; o, optic; ch, cheliceral; pp, pedipalpar ganglion 1, 2, 3, 4, 

 ganglia of the nerves to the legs. 

 Fig. 4. Dissection showing the relations of the nerve mass to the endosternite (e) ; eg, part of the 

 spongy terminal portion of the coxa! gland; my, the mid-gut with its diverticula; on, optic 

 nerve; ch, nerve to chelicera ; pp, double nerve topedipal]); 1, double nerve to 1st leg; 

 ckr, chitiuous rod (c/. PI. XXVIII. fig. 15). 



5. The same, with the heart (/<) ; the mid-gut {mg) raised off the endosternite, showing the blind 



pocket of the oesophagus (cp) ; on, optic nerve; ch, cheliceral nerve; ch' , nerve to cheliceral 

 muscles; e, endosternite; /w_r/', the positions of the lst-3rd mid-gut diverticula, the 3rd cut 

 shoi't ; eg, part of the terminal portion of the coxal gland. 



6. Central nervous system of G. arabs dissected out. L, labral nerves ; ittig, nerve to the stigma ; 



chr, chitinous rod {cf. PI. XXVIII. fig. 15) ; eg, position of the principal coils of the coxal 

 glands ; ab, abdominal ganglion just posterior to the diaphragm ; g, nerve to the genital gland ; 

 ht ^2' l-i} hi double nerves to the legs ; chf, folds of chitin under which the uerve passes 

 [cf. PL XXVIII. fig. 15) ; D, position of the diaphragm. 



7. Nearly median longitudinal section through the eye. post, posterior ; ant, anterior ; fl, deeply- 



staining flexible ring of chitin round the lens, allowing of some movement; i, iris-like fold; 

 sp, spongy tissue filling the fold and surrounding the eye like a cushion ; b, blood-plasma 

 and cells; m, connective-tissue membrane cutting off the eye from the rest of the body- 

 cavity. 



8. Much magnified portion of the preceding; /, portion of the lens; hi/, hypodermis layer 



secreting the lens ; r, long retinal cells with nuclei ; Ic, canals for the fluid permeating the 

 whole organ ; sp, spongy tissue in the iris-like fold. 



9. Section further in towards the median line cutting the lens almost tangentially ; c, irregularities 



in the outer layers of chitin covering the lens as if it had shrunk ; fl, staining flexible chitin ; 

 og, ganglion opticum. 



10. View of the tip of a pedipalp of Galeodes arabs. 



11. Side view showing the thickenings of the chitin forming a hinge; v, ventral; d, dorsal; 



ss, group of specialized sensory cells. 



12. Longitudinal section through the tip of a pedipalp; d, dorsal; v, ventral; i, aperture of 



invagination ; se, sensory epithelium, shrunk away from the ventral surface of the invagina- 

 tion ; ten, tendon for opening the lips ; nii, muscle of the same ; m.,, muscle attached to 

 tendon drawing down the invagination — the tendon is covered with epithelial, and scattered 

 pigment, cells ; tr, trachea ; n, nerve to the hairs and sensory cells [ss, fig. 1 1) on the 

 dorsal side of the limb. 



13. Section through the tip of a pedipalp cut slantingly, the sensory epithelium (se) (magnified 



in 13 a) shrunk away from the cuticle which carries the fine sensory hairs ; i, the cavity of 

 the invagination. 



14. A portion of this cuticle showing the thick longitudinal constituents of the lattice-work ; the 



fine transverse elements not shown. The fine sensory hairs are so closely packed that their 

 tips together form a wavy and ajjparently continuous surface. 



15. Ifi, 17. Anterior, posterior, and lateral aspects of the protrusible organ in its protruded con- 



dition as seen on a spirit sj)ecimen of G. arabs from Shaloof, near Suez, in the Nat. Hisi. 

 Mus. S. Kensington. 



