28 



Hydranthei) Imr 20 — 25 proximale Tentakler, ca. 8 mm. 

 lange, og distale Tentakler i flere tætstillede Eækker. 6 — 12 

 iigrenede Blastostyler. 



Gonosome. Fastsiddende motlusoide Gouoforer, uden 

 Kadialkanaler. men med 4 rudimentære Tentakler. 



Findested. St. 52, St. 267. Reykjavik. 



Tubularia prolifer, Agassiz. 



(Tab. I, Fig. 6). 

 Syn.: Hybocodon prolifer, Agas. (4). 

 Syn. V: T. simplex. Alder , G. 0. Sårs (07). 



Trophosome. Hydrocaulu-s ugrenet, roribrmig. ud- 

 caar fra forgrenet Hydrorhiza: optræder enkeltvis. Længde- 

 stribiiiiig. ingen Krave. Høide ca. 5 cm. Hydranthen har 

 14 proximale Tentakler og distale Tentakler i to vel ad- 

 skilte Kredse. 8 Blastostyler sidder i en Kreds omtrent 

 midt mellem de proximale og distale Tentaklei'. 



Gonosome. Fri Meduse med 4 Kadialkanaler og 1 

 sterkt udviklet Tentakel, der ved sin opsvulmede Basis 

 viser Anlæg til 4 nye Meduser, allerede forend den forstc 

 har løsrevet sig. 



Denne Art er beskrevet af Afiassi-:, som ogsaa liar 

 givet en Kække meget karakteristiske Afhildninger af den: 

 men den er liidtil ikke fanden paa den europæiske Side af 

 Atlanterhavet. 



Dens Trophosome ligner noget Tiihnlariti laryii.r. 

 men dens Hydrocaulus viser en svag Længdestribning iste- 

 denfor Ringe hos T. larynx, og dens Optrædeu er ganske 

 forskjellig, idet den som Regel optræder alene — efter 

 Agassiz skal det dog kunne forekomme at flere udgaar fra 

 samme Hydrorhiza. — Hydranthen har, selv om Blastosty- 

 lerne ikke er udviklet, et karakteristisk Kjendemerke i 

 Anordningen af de distale Tentakler i to vel adskilte 

 Ki'edse. Men det mest eiendommelige ved denne Art er 

 dog Blastostylerne med de fra dem anlagte IMeduser. 



Blastostylerne danner en tæt Kreds omkring Midten 

 nf Hydranthen i en betydelig Afstand fra Kredsen af de 

 proximale Tentakler. De er forgrenede og de enkelte 

 Grene deler sig som Regel skjærmformig i tre eller fire 

 Smaagrene, der hver bærer en Meduse. Paa det af mig 

 undersøgte Exemplar er ingen Meduser fuldt udviklede, og 

 de danner med sin ene sterkt opsvulmede Tentakel, som i 

 Størrelse næsten kan maale sig med hele den ovrige Del 

 af Medusen, en meget paafaldende Figur. Man ser tydelig 

 de fire Eadialkanaler, af hvilke en, — den som fortsattes i 

 Tentaklen. — betydelig overgaar de andre i Udvikling; 

 og man kan se Manuhriet, der, endnu uden nogen Mund- 

 aabning, rager frem over Klokkeranden. Ved Basis af 

 Tentakelen — lidt nedenfor dens tykkeste Parti — ser 

 man 4 Knuder, symmetrisk anordnet i Par paa begge Sider 

 a f Tentakelens Midtlinie, de proximale er smaa, ægformige, 

 medens de to Distale er større og af en uregelmæssig 

 Bygning. Det viser sig ved Snitserier, at disse Knuder er 



The hydrantli has from 20 to 25 proximal tentacles, about 

 8 mm. long. and several closely-disposed rovvs of distal 

 tentacles. Fi^om G to 12 unramified blastostyles. 



Gonosome. Fixed medusoid gonopliores, vvitliout 

 radial canals, but with 4 rudimentary tentacles. 



Locality. Station 52, Station 267 ; Reykjavvik. 



Tubularia prolifer, Agassiz. 



(Pl. I, fig. 0). 



Syn. : Hybocodon prolifer, Agas. (4). 



.Syn.':': T. simplex, Alder . G. 0. Sårs (07). 



Trophosome. Hydrocaulus unramified, tubular, sprin- 

 ging from ramified hydrorhiza; occurrence solitary; longi- 

 tudinal striping. no collar ; height about 5 cm. The hy- 

 drantli has 14 proximal tentacles, and two distinct circles 

 of distal tentacles. Eight blastostyles in a circle al)out 

 midway Ijctween tiie proximal and the distal tentacles. 



Gonosome. Free-svvimming medusa witli 4 radial 

 canals and 1 highly-developed tentacle, which exliil>its. at 

 its svvollen base, the bud-rudiments of 4 new medusæ, 

 even before the first has become detached. 



This species is described by Afjassiz, who has also 

 given a series of very characteristic illustrations of it; but 

 it lias not hitherto been found on this side of the Atlantic. 



Its trophosome somewliat resembles that of Tiihnhiria 

 larynx, hut its hydrocaulus exhibits a faint longitudinal 

 striping, in place of the rings in T. larynx. Its occur- 

 rence is also quite different, as it is generally solitary, 

 although, according to Agassiz, several may sometimes 

 spring from one hydrorhiza. Tlie hydranth lias a charac- 

 teristic distinguishiiig feature, even if the Idastostyles are 

 not developed. in the arrangement of the distal tentacles 

 in two distinct circles; but the most jjeculiar feature of 

 this species is the blastostyles with thcir rudimentary 

 medusæ. 



The blastostyles form a tliick ring around the mitldle 

 of the hydranth, at a considerable distance from the ring 

 of proximal tentacles. They are ramified, and each ramns, 

 as a rule, divides, in the form of an umbel, into 3 or 4 

 small branches, each bearing a medusa. On the .specimen 

 examined by me none of the medusæ are full}- developed ; 

 and with their solitary greatly swollen tentacle, which is 

 nearly equal in size to tlu' whole of the medusa, they liave 

 a very strange appearance. Tiie 4 radial canals are di- 

 stinctly visible, one of tiiem — that of whicli the tentacle 

 is a continuation — considerably surpassing the otliers in 

 development. The nianubrium is also visible, projecting, as 

 yet without any oral aperture, beyond the edge of the beil. 

 At the base of the tentacle, a little below its tliickest part, 

 4 processes are to be seen, syranietrically arranged in pairs 

 on each side of the median line of the tentacle; the proxi- 

 mal processes are small and oviform, while the two distal 

 ones are larger, and of an irreaiular structure. From the 



