22 



Denne Art skiller sig tydelig fra de to foregaaende, 

 ved sine talrige og lange proximale Tentakler, saavel som 

 Ted de næsten traadlbrmede Blastostyler, der i Længde 

 maaler sig med Tentaklerne, og som ved sin tætte Besæt- 

 ning af djbt purpurfarvede Gonoforer giver denne Hy- 

 droide et sjelden pragtfuldt Udseende. 



Jeg har kun havt Anledning til at undersoge Brud- 

 stykker af denne Art, men disse, i Forbindelse med Prof. 

 Sars"s Tegning af den efter levende Exemplarer, er dog 

 nok til at skafie et nogenlunde helt Billede af Artens 

 Eiendommeligheder. 



Findested. St. 137. 



Gen. Corymorpha. 

 Corymorpha nana, Alder (6). 



(Tab. L Fig. T). 



TrophoBome. Hydrocaulus rørformig med hindeagtig 

 Perisarc, bæier i den proximale Ende fine Heftetraade. 

 Hydranthen har 15 — 25 proximale Tentakler, 10—15 mm. 

 lange, og 16— 18 distale i en Kreds. Blastostyler (10—15) 

 ugrenede, danner en Kreds liae indenfor de proximale 

 Tentakler. 



Gonosome. Faa Gonoforer paa hver Blastostyl, lul- 

 vikler sig til fri Meduser med 4 Eadialkanaler og 1 fuldt 

 udviklet Tentakel, samt 4 rudimentære. 



I sin Beskrivelse over denne art omtaler Alder (47), 

 at han har seet et enkelt Exemplar, der indenfor de proxi- 

 male Tentakler bar fuldt udviklede Meduser, medens alle 

 de øvrige istedenfor disse Meduser bar en Kreds af eien- 

 dommelige klumpede Legemer med forskjellige Udbugt- 

 ninger paa sin Overflade. 



Nordh.-exp.'s Exemplar, der i sin Bygning forovrig 

 fuldstrendig stemmer med Alders Beskrivelse af ('. naua, 

 bærer en Kreds af temmelig korte og tykke Blastostyler, 

 fra hvis distale Ende Meduseknopperne aulægges. Det er 

 ikke usandsynligt, at de omtalte uforstaaelige Legemer paa 

 Alders Individer, netop er saadanne ganske unge Blasto- 

 styler, paa hvis Overtiade Knopperne endnu kun viser sig 

 som Ujevnheder. En Sammenligning af Alders lllustration 

 med min (Fig. 7 a) «totter en saadan Formodning. At Bla- 

 stostylerne paa det ene Exemplar, der bar Meduser, har 

 været forsvindende i Forhold til de fuldt udviklede IVIedu- 

 sers Størrelse, og saaledes har undgaaet Alders Opmærk- 

 sonihed kan ikke overraske, da det er meget almindeligt, 

 at Blastostylerno aftager i Størrelse, specielt i Tykkelse 

 eftersom Gonoforernes Størrelse tiltager. 



Findested. St. 261. 



This species is clearly distinguished from the two 

 preceding ones by its numerous long proximal tentacles, 

 and by the alraost filiform blastostyles, whose length equals 

 that of the tentacles, and which, owing to the deep purple 

 gonophores with which they are thickly covered, impart a 

 magnificent appearance to this hydroid. 



T have only had the opportunity of examining frag- 

 ments this species. but these, combined with Prof Sars's 

 drawing of the animal from living speciraens, are sufficient 

 to give a fairly complete idea of the pecularities of the 

 species. 



Locality. Station 137. 



Gen. Corymorpha. 

 Corymorpha nana, Alder (6). 



(Pl. I. fig. 7). 



Trophosome. Hydrocaulus tubular, with mcmbranous 

 perisarc; at its proximal end fine attaching filaments. The 

 hydranth has from 15 to 25 proximal ttaitacles. 10 — 15 

 mm. long, and from 16 til 18 distal tentacles in a circle. 

 From 10 to 15 blastostyles, unraraified, forming a circle 

 just within tliat of the jn-oximal tentacles. 



Gonosome. Only a few gonophores on eacli blasto- 

 style; developed into free medusæ with 4 radial canals, 

 and 1 fully developed, and 3 rudimentary tentacles. 



Alder (47j, in his description of tiiis siiccies. men- 

 tions having seen a single specimen tliat had fully-deve- 

 loped medusæ within the ring of proximal tentacles, while 

 all the others, in their place, had a ring of peculiar tube- 

 rous bodies with various lumps on their surface. 



The N. Atlan. Exp. specimen, wliich. in other respects, 

 agrees exactly witd Alders descprition of C. naua, has a 

 circle of rather short, thick blastostyles, from whose distal 

 end the mednsabuds spring. It is not improbable that 

 the above-mentioned incomprehensible bodies on Alder's 

 specimens are mercly very young blastostyles of this de- 

 scription, upon whose surface the buds as yet have only 

 the appearance of surface inequalities. A comparasion of 

 Alders illustration with mine (fig. 7 a), will bear out a sup- 

 position of this kind. It is not surprising that the bla- 

 stostyles on the one specimen with medusæ were very small 

 compared with the size of the fiilly-developed medusa, 

 and have thus escaped Alde7-'s notice, as it is very usual 

 for the blastostyles to decrease in size, esjjecially in thick- 

 ness, as the size of the gonophores increases. 



Locality. Station 261. 



