TIIK AKTIIROGASTKA. 



321 



which correspond with the third, fourth, fifth* and sixth, of 

 the free terga. Each of these bears a pair of oblique slita, 



Fio. 84. Scorpio afer.A, tereal, and 5, sternal, view of the body ; At, chellcene ; 

 iv', pedipalpi ; v', vi', posterior pair of cephalic appendages ; vn', vm', anterior 

 thoracic limbs; Pt, pectines ; St, stigma; Cth, cephalo-thorax. (After Milne- 

 Edwards and Dug^s. 1 ) 



which are the openings of the respiratory organs (Fig. 85, e). 

 The sterna of the first and second free somites (ix, x) are very 

 small ; that of the first carries the valves which cover the 

 genital aperture ; that of the second bears a pair of very 

 curious appendages, somewhat like combs, which are termed 

 the pectines. The nervous trunks which enter the pectines 

 a iv distributed to the numerous papilla 1 which cover them, 

 and are probably tactile in function. Thus there are twelve 

 somites behind the eye-bearing shield, and none of these are 

 provided with appendages, unless the pectines be such. 



The truncated anterior extremity of the body, beneath the 



i " Regne Animal," Illustrated Edition. 



