16 THE ANATOMY AND DEVELOPMENT OF PERIPATUS NOVAE-BRITANNIAE. 



" an enormously long spermatophore which is surrounded by a horny case " and has 

 " precisely the same structure as that described by Gaffron in P. edwardsii." 



In P. edwardsii we are informed by Gaffron (6, p. 154) that the spermatophore 

 is a thread-like structure exceeding 4 centimetres in length. This spermatophore has a 

 definite and complicated structure for the details of which Gaffron's excellent Memoir 

 should be consulted. 



In P. novae-britanniae the vasa efferentia, vasa deferentia and ductus ejaculatorius 

 contain abundant loose felted spermatozoa, but I have observed no spermatophore. 



It must not be supposed that the short median ductus ejaculatorius of the New 

 Britain species is the equivalent of the entire unpaired duct of P. edivardsii and P. 

 novae-zealandiae or even of P. capensis, but it is only equivalent to that portion of the 

 duct in these species which is lined by a chitinous intima and is the true ductus 

 ejaculatorius. In the Cape species the greater part of the terminal duct, upwards of 

 three-fourths, is ductus ejaculatorius and is characterised by its muscular wall and rich 

 supiily of tracheae (Moseley). In P. edwardsii the terminal portion of the unpaired 

 duct which, by its muscular walls and chitinous intima, discloses the character of an 

 ejaculatory duct has a length of 2 centimetres (Gaffron). 



In P. novae-britanniae what there is of an unpaired duct is all ductus ejaculatorius 

 and is alone lined by a chitinous intima. [See Fig. 20 and remarks thereon.] 



Pygidial glands. These are a pair of large tubular glands only present in the 

 male and homologous with the accessory glands of the African and Australian species 

 and with the anal glands of the Neotropical species. They resemble the corresponding 

 glands of the other species in their general structure but differ altogether in their 

 method of discharging to the exterior (Figs. 19 — 22). The glands generally have a 

 dorsal position. The anterior moiety is whitish in the preserved condition while the 

 posterior moiety has a straighter course and a smooth glistening brown-coloured 

 surface with a white axis running up the centre of the tube. The appearance of a 

 white axis is presumably caused by the chitinous intima which lines the ectodermal 

 portion of the gland. The whitish, coiled, anterior portion of the gland is the 

 mesodermal portion. Upon arriving near the posterior end of the body, the two 

 pygidial glands enter a large muscular bulbus, the pygidial bulbus (Figs. 19 — 22, 

 p. b.). The latter opens to the exterior in the dorsal middle line immediately above 

 and in front of the iipper margin of the terminal anal opening (Fig. 19, p. o.). In 

 P. edwardsii the anal glands are so called because they open at each side of the anus 

 as shown by Gaffron. In P. novae-zealandiae, they are described by Miss Sheldon as 

 accessory glands opening near the posterior extremity of the body, the two openings 

 lying outside the nerve-cords and therefore widely separate. In P. lenckarti, Fletcher 

 has described the external openings of the accessory glands as occurring close together 

 between the generative orifice and the anus. Finally in P. capensis they discharge 

 into the terminal portion of the ductus ejaculatorius (Balfour 2). 



In P. novae-britanniae the muscular coat of the ductus ejaculatorius is not very 

 thick, while the pygidial bulbus occupies a large portion of the mass of the body in 

 that region, and this is particularly the case in late uterine embryos. In P. capensis on 

 the other hand the muscular coat of the terminal end of the ductus ejaculatorius is 



