KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 50. N:0 5. 7,3 



brought close together, so that tliey open in the same diverticle, and in close relation to 

 a saccular protriision of the vagina, seemingly a rudiment to a spermatocyst. The first 

 step to a bipartition of the bursa copulatrix is hereby estabhshed. 



The genital ducts of V. undata (Text Fig. 4) are most hke those of V. phcatihs. 

 The vagina is rounded and furnished with very thick walls, which is also the case Mdth 

 the vas deferens. Tliis emerges from the hinder part of the vagina and receives the 

 prostata duct close outside its starting-point. The opening of the hermaphrodite duct 

 is in the same diverticle of the vagina as the mouth of vas deferens, Bursa copulatrix 

 is strongly curved, its posterior -end being bent down. On its outer side a small bladder 

 rises, communicating ^^dth the vagina as well as with the biu"sa copulatrix; its epithelium is 

 lower and it seems to be a rudimentary spermatocyst. The proximal part of the vas defer- 

 ens runs freely above the body-wall in front of the female orifice, fixed to the body only 

 by the thin integument. Then it dives into the muscle-wall and continues to the penis. 

 The structure of the penis is peculiar. It forms a somewhat flattened muscular process 



s, 





^=< 



h.a. 



v.d) 



Fig. 4. The Genital Apparatus of Velutina undata Brown. 



with the distal part bent backwards and dilated; from the outer edge of this djsc a nar- 

 rower apical stiff prolongation sets out, foUowing the lower edge forwards and terminat- 

 ing with a knob like a pin's head. 



Onchidiopsis glacialis (M. Särs 1851). 



Pl. 2, Figs. 17, 18, 23, 24; Pl. 5, Figs. 3, .5, 32, 33. 



Habitat:^ 



Spitzbergen: Bel Sound, 30 — 35 fms, stones, zooph}i;es (Torell), 1 sp., 1. an. 33, sh, 

 24 (Pl. 2, Figs. 18, 24; Pl. 5, Fig. 32); D:o, 35^0 fms, stones zooph3d:es (Torell), 2 sps, 

 max. 1. an. about 32, sh. 26—28. — Waygat Islands, 79° 20' N. 19° E., 30 fms, rocks 

 (Malmgren '% 1861), 2 sps, max. 1. an. 27, sh. 24; D:o, 60 fms, clay (Malmgren 'Vs 

 1861), 2 sps, max. 1. an. 33, sh. 21. 



Beeren Island— Hope Island, 75° 49' N. 24° 25' E., 80 m, rocks, bottom temp. 

 —1.42° (^Vo 1898), 3 sps, max. 1. an. 30, sh. 23. 



* I have seen a specimen of this species from Hekla's Haven, E. Greenland, in the Museum at Copenhagen. 



K. Sv. Vet. Akad. Handl. Band 50. N:o t,. 10 



