( Ixxix ) 



The clasper of Spliingidae is normally sole-shaped (PI. XXXVIII. f. 5), 

 with the dorsal and ventral margins ronnded. The size is variable. The 

 jirincipal modifications are as follows : — 



(1) Modifications by rednction. AVhen only shortened, the clasper assnmes 

 the stnmpy form as illnstrated by Pi. XXXII. f. 18. 10. When only narrowed, 

 we have the narrow clasper of CaUamhuh/x (PI. XXXIV. f. 19. 20), a common 

 type among Ambulicinae. The longest and jiroportionally narrowest clasper is 

 fonnd in Hinvintoides and Sf.iia (PI. XLVII. f 1. 15). The broad clasper 

 tonches the tenth tcrgite, while the narrow clasper stands apart from it, if the 

 rednction has taken place in the dorsal portion of the clasper. The interspace 

 between clasjier and tenth tergite is then covered by the long fringe of hairs of 

 the former. 



(~) Modification by division and the develoi)ment of a special armatnre 

 (apart from harjie). Lobes, processes, teeth appear very often in connection 

 with the rednction of the clasper. Compare PI. XXXII. f. 12. 13 ; PI. XXXIII. 

 f. 6. K). 21. 22. 23 ; PI. XXXIV. f. 3. 2s ; PI. LI. f. 22 ; PI. LII. f. 1. 6. 



The clasper is not solid, bnt consists of an external and an internal i)late, 

 between which the remnant of the matrix is found. It is an outgrowth from 

 the segment, and can best be likened to the wings. The inner sheath is more 

 or less covered with hairs, which are often very dense, very stiff and long. The 

 hairs of the distal half of the clasper are directed dorso-basad (PI. XXXVI. 

 f. 9 ; PI. XXXVII. f. 15). They are not generally drawn in the figures. The 

 inner sheath is in most species raised into special armatures. There is 

 very often a consjiicnons subdorsal longitudinal setiferons fold (PI. XXXVI. 

 f. 18. 19. 2n). A dorso-basal ridge or process is commonly found among 

 Ambulicinae; it is seldom spiniforra {pdh, PI. XXXIII. f. 21 ; PI. XXXVIII. 

 f. 7), mostly almost membranaceous, compressed and beset at the edges with 

 setiferons tubercles {pd, PI. XXXII. f. H — 11. 15. 17. 18). The ventral armatnre 

 of the clasper is termed the harjie : it begins at the ventral basal (hollow) 

 incrassation of the clasper, which is the principal part of the sternite proper, 

 and extends more or less distad and dorsad. If the harpe is reduced, the line 

 of sejiaration between the triangular sternite and the main part of the clasper 

 (= pleura) is plainly visible (PI. XLV. f. 26 ; PI. XXXL f. 2 ; PI. XXXV. f. 20), 

 but as a rule the ridges or processes of which the armatnre consists are continued 

 over the pleura, the inner sheath of which takes part in building up the 

 structure. The harpe is so diversified tliat it is impossible to give a general 

 description of this armature. It is on the whole more complicated in the 

 Sjjhingidae usemaiiojtkorae than in the Spkingidae semanopkorae, but we find also 

 among the latter sometimes species with formidable-looking harpes (PI. XLVIII. 

 f- n — 27). The harpe of Choerocampinae is as a rule a simple, slightly curved, 

 slender process (PI. LII. f. 8) ; an armature of the same type is not rarely 

 met with among Philampelinae (PI. L. f. 32). As a rule the processes of the 

 harpe lie upon the inner surface of the clasjier ; bnt occasionally the sternal 

 part alone forms the armature, and is situated below the main part of the 



