IG 



muskler, lolier de tbrste ca. 5 nira. nedover straaleformigt, 

 medens de sidste findes i tæt lag mellem siphonerne og 

 nedover ca. 3 mm. Mellem aabningerne sees et ganske 

 lidet, mere muskeltVit feit, hvor gangliet ligger. Fra denne 

 øvre, stærkt mu.skiilose del strækker sig talrige baand af 

 korte muskler nedover kroppen. Den venstre side betyde- 

 liftt rigere forsynet med disse end hoire. 



Tentaklerne 9 temmelig store, sammentrykte med ikke 

 mange, men fine grene (fig. 11); 9 smaa imellem de store. 



Flimregruben enkel, svagt opboiet; aabningen halv- 

 maaneforraig med den konkave side vendende noget bagud 

 og tilvenstre (fig. 10). 



Gangliet lidt tilvenstre for og delvis under fiimre- 

 gruben. 



Dorsalfolden med glat rand, standser ved svælget. 



Gjællesækken med 7 stærkt krummede hoie folder paa 

 hver side; Iste til ote fold fra dorsalfolden har 7 — S rib- 

 ber, 6te 6 og 7de 5, hvoraf den ventrale ribbe er hoi, 

 baandagtig. De to dorside ribber er oftest lasere forbundne 

 med folden og lober ialraindelighed i nogen afstand fra 

 denne. Tværribberne fine og hoie. Under ribberno findes 

 i hvert felt 2 dylie infundibula, som i 6te og 7de fold atter 

 deler sig i 2 mindre. Spiraklerne mellem foldene temmelig 

 korte, rette eller svagt hoiede ; de af disse og infundibula 

 dannede spiralsystemer betydelig længre end brede. Over 

 spiraklerne lober talrige anastomoserende aarer, som hist og 

 her er forsynede med smaa knopformige ophoiniiiger (fig. 12). 



Svælget hoit oppe i gjællesækken (6 mm. fra fiimre- 

 gruben) og omgivet af en fortykket læbe. Tarmen danner 

 en lukket, næsten horizontal slynge (fig. 9). Anus er trang, 

 med svagt firedelt rand. 



Kjonsorgauer store, især det hoire (7 mm. langt); det 

 venstre ligger over tarmslyngen. Begge er fint lappede 

 med sædsække i randen, medens man paa nedsiden ser en 

 lang, svagt grenet ovidukt, der mod kloakrummet aabner 

 sig paa en fremspringende tap. 



Nyresækken som sædvanlig under hoire kjonsorgan. 

 svagt boiet. 



Ildbredelse. 1 exemplar fundet ved Gjesvær (71" n. 

 br.) af hr. stipendiat Huitteldt-Kaas (1894). 



ternal circular muscles. the former of whicli radiate down- 

 wards from the siphons about 5 mm., while the latter are 

 found in a thick laver between the siphons and downwards 

 for aljout 3 mm. Between the apertures there is a very 

 small, less muscular space in which the ganglion is situated. 

 From the ujiper, more muscular part, numerous bands of 

 short muscles extend downwards over the body. the left 

 side being much more plentifully supplied with them than 

 the right. 



Tentacles 9 in number, rather large, compressed, with 

 few, but fine rami (fig. 11). Nine smaller tentacles among 

 the large ones. 



Dorsal tubercle single, slightly bent npwards; the 

 opening crescent-shaped, with the concavo side turned some- 

 what backwards and to the left (fig. 10). 



Ganglion a little to the left of, and partly lielow the 

 dorsal tubercle. 



Dorsal lamina with smooth margin; ends at the æso- 

 phageal aperture. 



Branchial sac with 7 very much curved high folds on 

 each side; the first o counting from the dorsal lamina, 

 have 7 or 8 bars, the 6th has 6, and the 7th, 5, the ventral 



bars l)eing high and 



ju-like. The 2 dorsal bars are 



generally more loosely attached to the fold, and usually 

 run at some distanco from it. The transverse bars are 

 fine and high. Beneath the bars. in each spact', there are 

 two dee[rinfundilnila, which, in the 6th and 7th folds, again 

 divide into 2 smaller ones. The spiracles between the folds 

 are rather short and either straight or slightly bent; the 

 length of tlie spiral systems formcd l)y them and the in- 

 fandil)ula, is considerably greater than the breadth. Above 

 the spiracles run numerous anastomosiug veins, provided 

 here and there with small bud-like proniinences (fig. 12). 



The æsophageal aperture is high up in the branchial 

 sac (6 mm. from the dorsal tubercle), and surrounded by 

 a thickened lip. The intostine forms a closed. almost hori- 

 zontal loop (fig. 9). The anus is nai'row, witii a slightly 

 four-lobed margin. 



Genital organs large, especially the right (7 mm. 

 long); the left ono is situated above the loop of tiie inte- 

 stine. They are both finely lobed, with sperm cells in the 

 margin, while on the inside, there is a long, slightly rami- 

 fied oviduct, which opens towards the cloacal cavity upon 

 a projecting process. 



Renal sac, as usual, beneath the right genital organ, 

 slightly curved. 



Distribution. One specimen was found at Gjesvær 

 (710 x. Lat.), by Mr. Huitfeldt-Kaas (1894). 



