36 



stor som Længden. Fordybningerne ligger temmelig dybt 

 nedsænkede, saaat de omliggende Kalkkorn omgiver dem 

 som en Vold; de er ligesom Pladerne fint granulerede. 

 Muligens bør de betragtes som Plader, sandsynligere ei- 

 det dog, at disse Fordybninger er „Radialskjoldene" og 

 den første Antydning til Ribberne ; Pladerne findes nemlig 

 spredt over Skiven uden nogen bestemt Orden, medens 

 Fordybningerne er ordnede parvise ved Armenes Basis 

 paa det Sted, hvor senere Ribberne udvikler sig. De 

 adskiller sig desuden fra Pladerne ved sin eliptiske Form 

 og ved at Midten ikke er opbøiet. 



Armene er ca. 10""" lang og forgrener sig to Gange, 

 den første Forgrening begynder i'" m fra Skiven, den anden 

 4 — 5»"" f r a den første. 



I Lymans store Arbeide over Challenger Ophiuriderne 

 omtales to unge Exemplarer af Gorgonocephdlus agassizii 



med en Skivediameter af 2.5""" og 7'""'. Det her omtalte 

 Exemplar synes at staa midt imellem disse to meil Hens] a 

 til Skivens Granulation. nærmest staar det et 4""" sturt 

 Exemplar, som Fischer beskriver fra Jan Mayen; det af- 

 viger dog fra alle tre, ved at de ganske mangler „Radial- 

 skjoldene - '. Disse mangler endvidere hos et 7""" og et 

 11""" stort Exemplar, si mi ligeledes blev indsamlet veil Jan 

 Mayen. Hus Gorgonocephahis ewenemis synes heller ikke 

 disse „Radialskjolde" eller Fordybninger at vane iagttagne, 

 idetmindste kan de ikke sees antydede paa Liitkens Teg- 

 ning af et 3""" og et 4.:.""" stort Exemplar 1 ). 



Som bekjendt undergaar denne Art ligesom de øvrige 

 til Slægten Gorgonocephdlus hørende Arter store For- 

 andringer under Væxten ; det for de fuldt udviklede Indi- 

 vider saa karakteristiske [Tdseende viser sig dog meget 

 tidligt. Allerede ved en Skivediameter af 20""" er det saa- 

 ledes ikke muligt at forvexle denne Art med de øvrige 

 tre nordiske. Ved en Skivediameter af 30""" er alle denne 

 Arts typiske Karakterer fuldt udviklede. 



Pindested. 



Station No. 18 1 stort Exemplar. 



— .. 124 2 unge Exemplarer. 



223 1 ungt Exemplar. 



— .. 362 15 større og mindre Exemplarer. 



— .. 363 11 — — — 



Udbredelse. 



Ved de norske Kyster er denne Art, saavidt vides, 

 kun lunden i Varangerfjorden, hvorfra der i Bergens 



') Addit. ad Hist, Ophiurid., parti, pag. 7!. Tab. II, fig. 1S&10. 



about half as much as the length. The cavities lie pretty 

 deeply depressed, so that the surrounding calcareous 

 grains enclose it like a wall; they are, like the plates, 

 finely granulated. Possibly they ought to be considered as 

 plates; it is, however. more probable that those cavities 

 are the radial shields and the first indications of the 

 ribs; the plates, namely, are found spread over the disc 

 without any definite order, whilst the cavities are arranged 

 in couples at the hase of the arms. at the points where 

 the ribs subsequently develope themselves. They distinguish 

 tbemselves, besides, from the plates, by their elliptical 

 form and by their middle not being elevated. 



The arms are about 10""" long and ramify twice. 

 The first ramification begins 4'"'" from the disc. the second 

 4 — 5""" from the first. 



In Lyman's important work on the Challenger Ophi- 

 urideans two young specimens of Gorgonocephdlus agassizii, 

 having disc-diameters, 2.5""" and 7'"'", are spoken of. The 

 specimen spoken of here seems to stand just between 

 those two with respect to granulation of the disc; it stands 

 closest to a 4""" large specimen which Fischer describes 

 from Jan Mayen: it differs, however, from all three, in 

 that they are completely awanting in the -radial shields". 



These are. further, absent in a 7 and a 1 1""" large specimen. 



which specimens were likewise obtained at Jan Mayen. 

 Xeither in Gorgonocephdlus eitcnemis do those -radial 

 shields" or cavities seem to have heen uliserved; at least 

 they cannot be seen indicated in Liitkeifs illustration of 

 a 3""" and a 4.5""* large specimen l ). 



As is known. this species, as well as the others 

 pertaining to the genus Gorgonocephalus, undergoes great 

 changes during growth. The appearance so characteristic 

 of the fully developed individual, presents itself, however. 

 very early. Already with a disc-diameter of 20""" it is 

 therefore not possible to confuse this species with the 

 other three nortbern species. With a disc-diameter of 

 30""" all the typical cha raet eristics of this species are 

 fully developed. 



Distribution. 



On the Norwegian coast this species has. so far as 

 is known. onlv heen found in the Varanger fiord, whence 



' Addit, ad Hist, Ophiurid.. parti. paa. 71. Pl. II. hgs. 1S&19. 



