17 



TcgetationstiiJ. Især sommer og; host, 

 mængder hele aaret. Sporer i november. 



do"; i siiiaa 



Forekomst. Ekersund og Cliristianiafjord november U3 

 {Hjort), Vestkysten juni 95 {Hjort) og juni 96 {S. MUJler), 

 Bergensfjord juni— august 96 (Nordgaard), Vestkysten fe- 

 bruar 96 {Nordgaard). 



Udbredelsp. Athmtcrhavet, Nordsøen, Skagerak, Kat- 

 tegat. 



10. Chætoceros laciniosum, Sdrntf (1895) p. 88, 

 tig. a — c. 

 Tab. I, fig. 4—7. 

 Syn. Ch. ilisfans. Cl. (18ir4) p. 14. T. II, Hg-. ■_' (non 1873). 

 „ breve, Schiitt (IS!).",) p. 38, flg. -i a, h. 

 ,. distans, Gran in Hjort (180.")) p. 40 — 41. 

 „ commutatmn, CL (ISOO, .")) p. 28, fio-. 9 — lo. 



Rette, ikke eller svagt snoede kjeder, bredde 10 — 42 ,«. 

 Cellerne i frontstilling rektangulære med kort fremsprin- 

 gende, udvendig afrundede hjorner. i sidestilling elliptiske. 

 Skallerne konkave, paa midten lavt hvælvede. Fin-amina 

 rektangulære-kvadratiske med afrundede hjorner, svagt ind- 

 snorede paa midten. Baaiidet langt cylindrisk, mindst '/a af 

 cellens længde (/). 



Kromatoforer 1 — 2, liggende op til den ene eller til 

 begge skaller, uregelmæssig lappede eller næsten hele. 



Hornene tynde, bøiede, udgaar fra skallernes indbøiede 

 hjørner næsten parallelt med kjedens længdeaxe indtil 

 krydsningspunktet, bøier saa af næsten tværs paa denne, 

 divergerende under en ret vinkel, to parallelt sagittalaxen, 

 de to andre næsten transversalt til hver sin side af sagit- 

 talplanet. 



Terminaliiorn differentierede, paa midten noget for- 

 tykkede, med afrundede, spiralstillede forhøininger, i front- 

 stilling næsten parallele, i sagittalstilling divergerende i en 

 spids vinkel. 



Hvilesporer glatte, beliggende noget ensidig i moder- 

 cellerne med undersiden vendt mod niodercellens nærmeste 

 skal. Primærskallen lioit pukkelformig hvælvet, sekuudær- 

 skallen næsten plan, svagt hvælvet paa midten. 



Vegetationstid. Hele aaret, især vinter og vaar. S])o- 

 rer i marts — juni. 



Forekomst. Vestkysten og Christianiatjorden november 

 93 {Hjort), Marstenen juni 95 {Hjort), Vestkysten februar 

 96 {Nordgaard), Drøbak fel)ruar— marts 96! Trondhjem 

 juni 96 (5'. MiiUer). 



Udhredelse. Nordsøen, Skagerak, Kattegat, Østersøen. 



II. Chætoceros constrictum. n. sp. 



Tab. I, tig. 11 — 13; Tab. 111, tig. 4-2. 



Kjederne rette, ikke snoede, bredde 14 — 35 ,«. 



Cellerne i frontstilling rektangulære med skarpe, kort 

 fremspringende hjorner og temmelig dybe indsnoringer ved 

 sømmene, i sidestilling elliptiske— cirkulære. Skallerne kon- 



Per/od of Vrgetation. Especially summer and autumn, 

 although in small quantities the wiiole year. Spores in 

 November. 



Occurrence. Ekersund aiul Christiania Fjord, Nov. 

 1893 (Hjort); "W. coast of Norway, .lune 1895 (Hjort) and 

 June 1896 (S. MiUler); Bergen Fjord, June to Aug. 1896 

 (Nordgaard); W. coast of Norway. Feb. lSd6 (Å''ordgaard). 



Distrihution. Atlantic Ocean, North Sea, Skagerak, 

 Kattegat. 



10. Chætoceros laciniosum, SddUt (1895) p. 38, 

 tigs. 5 a — c. 



Pl. I, fig.s. 4-^7. 

 Syn. Ch. distans, Cl. (1894) p 14, Pl. II, fig. 2 (not 1873). 

 „ breve, Schutt (1895) p. 38, fig. 4 a, b. 

 „ distans, Gran in Hjort (18i)fi) pp. 40, 41. 

 „ comniutatiim. Cl. (1S9(>, .'>) p. 28, figs. 9, 1(1. 



Filaments straight, only slightly, if at all twisted, 

 width 10 — 42 //. Cells, in a iioiit view. rectangular with 

 shortly projecting, outwardly rounded angles; in a side view, 

 elliptical. Valves concave, slightly convex in the middle. 

 Foramina rectangular to square. with rounded corners, 

 slightly constricted in the middle. Hoop lang cylindrical, 

 at least Vs of the length of tlie cell (?). 



Chromatophores 1 or 2 h'ing close to one valve, or 

 one to eaeh valve, irregularly lobed or almost entirc. 



Setæ thin, curved, issuing from tiie incurved angles 

 of the valves almost jiarallel witli the long axis of tlie 

 tilament, as far as the point of crossing, then turning oS 

 almost perpendicularly to it, diverging at a right angle, 

 two parallel to the sagittal axis, the other two almost 

 transversely to opposite sides of the sagittal plane. 



Terminal setæ differentiated, somewhat thickened in 

 the middle, with rounded, spiral prominences, almost pa- 

 rallel in a front view. in a sagittal view diverging at an 

 acute angle. 



Spores smooth, situated rather at one side in the 

 parent cells, with tiie under surface turned towards tlieir 

 nearest valve. Primary valve with a high inunp, secondary 

 valve almost Hat, slightly convex in tiie middle. 



Period of Vegetation. The whole year, especially 

 winter and spring. Spores from ^larch to June. 



Occurrence. W. coast of Norway and Christiania 

 Fjord, Nov. 1893 (Hjort); Marstenen, June 1895 (Hjort); 

 W.coast of Norway, Feb. 1896 (^^orf/^^aard); Drøbak, Feb. 

 and March 189(): Trondhjem. June 1896 (S. MiiUer). 



Distrihution. North Sea, Skagerak, Kattegat, Baltic. 



II. Chætoceros constrictum, n. sp. 



w. 1. tigs. 11—1:;; ]'i. III. fig. 42. 



Filaments straight, not twisted, 14 — 35 /( wide. 



Cells, in a front view, rectangular, with sharp, slightly 



projecting angles, and rather deep constrictions at the 



sutures; in a side view, elliptical to circular. Valves con- 



3 



