COMPARATIVE MORPHOLOGY OF THE GALEODID^. Ill 



Fig. 14. Hypothetical restoration of the common racial form. L, labrum ; I, labium, the latter being 

 the sternum of the 1st segment; tliese together formed the primitive beak; 1, cheliccra?, 

 limbs of 1st segment ; 5/3, .':ind sternite ; 2, pedipalps ; 3, 1st leg. The abdominal limbs 

 with stigmatic apertures are shown along the whole abdomen, the last pair on segment xii. 

 probably forming the sting of Scorpio, thereby accounting for the paired poison-glands ( /)(/.) 

 The dotted lines indicate the number of the abdominal segments subsequently specialize<l 

 for distension, in two cases leaving a few segments to form a " tail.'' S, Scorpio ; T, Thely- 

 phonus ; G, Galeodidae and Spiders. 



15. Thick portion of the cuticle, showing the outermost refractive or glassy layer (//), followed by 



many layers of softer laminated chitin, traversed by canals containing deeply staining 

 protoplasm and pigment. These canals terminate in the glassy layer. The hypodermis- 

 cells have broken away, leaving small groups of deeply-staining points, which are the 

 proximal ends of the protoplasmic processes traversing the chitinogenous layer. On the 

 probable nuclear character of these processes, cf. text, p. 331. 



16. Cuticle from the pedipalp of a Galeodes. Fusiform masses of olive-green pigment {pii/) send 



up processes which traverse the chitinogenous layers, similar fusiform masses being already 

 incorporated in the cuticle. (/, thin glassy layer. 



17. Portion of the thick and especially hard and brittle cuticle in which the fine canals ti'aversing 



the chitinogenous layers become wavy before tapering off into the glassy layer {ff). 



Plate XXX. 



Fig. 1. Portion of thick cuticle of Euscorpio. y, the very tliick, clear, glassy layer ; h, hard refractive 

 layers ; ch, softer chitinogenous layei-s. On the blind canal [sp] traversing the cuticle, 

 cf. text, p. 334. 



2. Lateral flexible membrane of Scorpio, g, glassy layer forming papillfe, the softer staining 



laminae [ch) thrown into folds. 



3. Section through flexible cuticle of abdomen of Lycosa (highly magnified), showing the folding 



of the glassy layer (g), rows of pores [p) in the furrows ; the outer portion of the chitino- 

 genous layers [ch) show no stratification, but are traversed by canals leading (?) to the pores. 



4. Method of suspension of a hair by the glassy layer, which also forms the outer covering of the 



hair, and lines the chamber in which the butt-end of the hair is suspended ; this end 

 is attached all round by a ring of radiating and deeply staining fibres {cf. fig. 7 b). 



5. The same, when the chitinogenous layers are thin. 



6. Flexible membrane of abdomen of Galeodes, showing the regular folding of the glassy layer, 



and the glassy chandler which prevents the hair from being thrust into the soft tissues. 

 7 a. To show the canal (c) which keeps the chamber above the fibres (//) in communication witli the 



body-cavity. This canal appears chiefly in long sensory hairs on the pedipalps and first legs 



{cf PI. XXXII. figs. 13, 14). 

 7 b. The radiating staining-fibres attaching the chitinogenous layer of the hair to the chitinogenous 



layer of the cuticle. These appear to be especially numerous in the long sensory hairs. 



8. A spine from a limb of Galeodes, showing its suspension bj' the glassy layer, and the spear- 



head arrangement to prevent the hair from being thrust into the tissues. 



9. Diagrammatic longitudinal section reconstructed from serial sections, showing the longitudinal 



[dim, vim) and dorso-ventral muscles {dv) ; m (shaded) indicates the musculature of the 

 chelicerse confined to the cephalic lobes ; eg, aperture of the coxal gland : e, point of origin 

 of the endosteruite ; stig, stigma ; r, ventral point of attachment of the rod supporting tlie 

 posterior edge of the cephalic lobes [cf. PI. XXVII. figs. 1-7) ; D, the diaphragm. 



54* 



