( Ixxix ) 



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

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

 princijial modifications are as follows : — 



n) Modifications by rednction. When only shortened, the clasper assnmes 

 the stumpy form as illnstrated by PI. XXXII. f. 18. lf». When only narrower), 

 we have the narrow clasper of Callamhuhjx (PI. XXXIV. f. 19. 'riJnj, a common 

 type among Amhulicinae. The longest and proportionally narrowest clasper is 

 fonud in Hiimntoides and Si>sia (PI. XLVII. f. 1. 1.5). The broad clasper 

 touches the tenth tergite, while the narrow clasper stands ajjart from it, if the 

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

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

 the former. 



(2) Modification by division and the development of a special armature 

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

 with the reduction of the clasj.er. C jmpare PI. XXXII. f. 12. 13 ; PI. XXXIII. 

 f. 6. 16. 21. 22. 23 ; PI. XXXIV. I .3. 2.s : PI. LI. f. 22 ; PI. LII. f. 1. 6. 



The clasper is not solid, bnt consists of an external and an internal plate, 



between which the remnant of the matrix is fonnd. 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 conspicnons subdorsal longitudinal setiferons fold (PL XXXVI. 



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



AmhuUcinoe; it is seldom spiniform {pilb, PI. XXXIII. f. 21 : PI. XXXVI II. 



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



setiferons tubercles (pd, PI. XXXII. f. — 11. \-k IT. 18). The ventral armature 



of the clasper is termed the harpe : 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 



(= i.leura) is i)]ainly visible (PI. XLV. f. 26 ; PI. XXXL f. 2 ; PI. XXXV. f. 20), 



bnt as a rule the ridges or jirocesses of which the armature consists are continued 



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



strncture. The harpe is so diversified that it is impossible to give a general 



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



S/jliiiiyidai' uiseinaiiophorue than in the Sphiiigkhn' in'manophorae. but we find also 



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



f. IT — 2T). The harpe of Choerocampinae is as a rale a simple, slightly curved, 



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



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



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



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



