14 



])ixa. 



33. Molgula nana, Kupft. 

 Tmustedt, .Hauch". V. 

 Udbredelse: Almindelig ved syd- og vestkysten, især 

 laminariestilke. 20 — 5i.) m. 



33 Molgula nana, Kuptt'. 

 Tiaustedt, ,,Hauclr'. V. 

 Distribution. General on the south and west coasts 

 of Norway, most frequently on Larainaria stalks. Depth. 

 20— oU m. 



34. Molgula occulta, Kupff. 

 Jacobsohn, Die Tunicaten d. weissen Meeres. 

 Traustedt, ,, Hauch", V. 



Udbredelse: Vor almindeligste Molgula ved syd- og 

 vestkysten, grov sandljund. 10 — 4M m. 



35. Molgula arctica, nov. sp. 



(TI. V, i\s. :i— 7). 

 Beskrivelse. Dyret frit, næsten kuglerimdt. 



Kappen temmelig tyk, stiv, brunlig, dog gjennemskin- 

 nende og ved hjælp af korte hæftetraade tæt bedækket med 

 sand og skalfragmenter. Intet nogent felt mellem aabnin- 

 gerne. 



Siplionerne meget korte, men siddende meget langt 

 fra hinanden (tig. 3). 



Muskulaturen svag, kun siphonerne og deres nærmeste 

 omgivelse mod kraftigere muskler, der dog kun strækker 

 sig et kort stykke nedover; mellom siplionerne lobor to 

 baand af korte tvrermuskler, der begrændser et stort, af- 

 langt, fuldstændigt muskelfrit felt, livori gangliet ligger 

 (fig. 3). 



Feltet foran tentaklerne glat. 



Tentaklerne ca. 14, afvekslende store og smaa, de 

 storre med faa og grove grene. 



Flimregruben liden, pærcformet; aabningen svagt Ijoiet 

 med den konkave side mod mundaabningen (fig. 6); det er 

 dreiet over mod hoire. 



Gangliet bagenfor og tilvenstre for tlimregrulien. 



Ringfuren gjør ved ilimregruben en ualmiiidelig lang 

 og smal udbugtning. 



Dorsalfolden helrandet, glat, standser ved svælget. 



Gjællesækken med 7 svagt krummede og lidet udpræ- 

 gede folder paa hver side. Folderne har faa, men kraftige 

 ribber (fra dorsalfolden : 4 — 5 — 5 — 4 — 4 — 3 — 2). Tvær- 

 ribberne kraftige. Kun 1 tiadt infundibulum i hvert feldt; 

 af og til i 5te fold og i Gte og 7de altid er infundibula 

 delt i 2 mindre, og her ligger disse ikke altid under ribbe- 

 komplekserne. men ofte tuldstændigt frit imellom dem (fig. 4). 



34. Molgula occulta, Kupff. 

 Jacobsohn, Die Tunicaten d. weissen Meeres. 

 Traustedt, ,.Hauch", V. 

 Distribution. The most common of Norwegian Mol- 

 gula on the south and west coasts, on bottom of coarse 

 sand: depth, 10— 4» i m. 



35. Molgula arctica, nov. sp. 



(I'l. v. tigs. :i— 7). 

 Deseription. Body unattached, ahuost globular. 



Height 



Lengtli 



Distance Ijetween si- 

 phons at base . , . 



Measured 

 out side tunic. 



With tunic 

 remoTed. 



13 mm. 

 12.. 'i mm. 



10. .'i mm. 

 10 mm. 



5 mm. 



The tunic is rather tliick, stifi' and of a brownish 

 sliade, tliougb traiislucent. By the aid of sliort attacliment 

 filaments, it is thickly covered with sand and fragments of 

 shell: no bare space between tlie orifices. 



Siphons very short. but widely separated (fig. 3). 



Musculature weak, only the siphons and immediate 

 surroundings being furnished with strong muscles, which 

 however e.xtend for only a sliort distance downwards. Be- 

 tween tlie siphons run two l)ands of short transverse mus- 

 cles, bounding a large, oblong space entirely without mus- 

 cles, in which the ganglion lies (fig. 3). 



Space in front of the tentacles, smooth. 



Tentacles about 14 in number, alternately large and 

 small, the larger ones with few and large rami. 



Dorsal tubercle small, pyriform; opening slightly curved, 

 with the concave side towards the oral aperture (fig. (i) : 

 it is twisted towards the right. 



Ganglion behind and to the left of the dorsal tubercle. 



By the dorsal tubercle, tiie peripharyngeal liand makes 

 an unusnally long and narrow wave. 



Dorsal lamina entire, smootii. ending at the æso- 

 phatie:il aperture. 



Branehial sac witli 7 slightly curved, and not strongly 

 marked folds on each side. The folds have few but power- 

 ful bars (from the dorsal lamina: 4 — 5 — 5 — 4 — 4 — 3 — 2). 

 Transverse bars strong. Only 1 flat infundibulum in each 

 space. Now and then in tlie 5th fold, and ahvays in the 

 6th and 7th, the infundibulum is divided iiito 2 smaller 

 ones, and then they are not ahvays situated beneath the 



