The Anatomy of Opisthopatus cinctipes. 109 



enlarged, 22-5 mm. x 2'5 mm. ; and of a large female from Dunbrody 

 (in spirits and moderately extended), 25 mm. x 3-5 mm. 



7. Diagnosis of the African Genera. 



This paper may be concluded with an amended diagnosis of the 

 two South African genera, and a revised synoptic table of the species 

 embodying the foregoing observations. For the sake of completeness, 

 Peripatus tholloni, Bouv., is included. Essential generic characters, 

 as distinguished from those which appear of secondary importance, 

 are printed in italics ; it is not, however, attempted to give a complete 

 list of all the differences between the genera, and we are, moreover, 

 insufficiently acquainted with the ova and the development of 

 0. cinctipes and P. tholloni. 



I. Peripatopis. — Genital opening mostly subterminal, the leg on 

 each side of it more or less rudimentary or at least much reduced in 

 size and much smaller than the legs of the first pair, ivith or ivithout 

 a foot arid occasionally eveot absent. No legs posterior to the genital 

 segment. No well-developed coxal organs present. Genital org a7is in ? 

 simple, without receptacula. Ductus ejacidatorius in the 3- provided 

 with a pair of accessory glands opening into its posterior end ; no other 

 accessory glands in the genital or postgenital segments, hut in the pre- 

 genital segrnent the crural glands are enormously enlarged and discharge 

 externally by an opening situated on a large non-retractile papilla on 

 the ventral surface of the leg.'^ Spermatophors mimite, oval. Legs 

 with 3 spinous pads, those of the 4th and 5th pair with the 

 nephridial opening situated in the proximal pad; feet with one 

 posterior and two anterior papillae ; legs of the genital segment not 

 used for walking; small crural glands may occur on most of the 

 other legs in both sexes. Genital opening in the ? longitudinal; 

 the embryos in the uterus all of nearly the same stage, except at 

 one season of the year (March, April, May), when two broods 

 overlap. Outer jaw with small accessory tooth at base of main 

 tooth ; inner jaw with no interval between the large tooth and the 

 series of smaller ones. South African. 



II. Opisthopatus. — Genital opening betiveen the posterior pair of 

 legs, ivhich are tv ell- developed and subequal in size to the legs of the 

 •first pair. No legs posterior to the genital segment. Most of the legs 

 with a locll-developed coxal organ. Genital organs in the $ luith 

 simplified receptacula seminis but no receptacula ovorum. Ductus 

 eiaculatorius in the ^ ivithout accessory glands, but the genital and a 



* The (f of P. clavigera, Pure, is not yet known. 



