paa den indvendige Side af den Rand, der begrændser 

 Furen, og som egentlig er Sidefladernes Begrændsning indad. 

 De sidde noget afvexlende. saa at. naar de lukke Furen, 

 ligger den ene skråa over paa den anden. Tab. I. Fig. 12 k. 

 Disse Klapper dannes af et fint, smukt Kalknet og ere 

 beklædte med en yderst fin. næsten gjennemsigtig Membran, 

 der er Fortsættelse af den Membran, som beklæder saavel 

 Armene som Pinnulerne, Tab. I. Fig. 13 c. 14. 



Paa de 7 nederste Pinnuler lindes Generationsorganet, 

 der er tapformigt og indtager næsten hele Ventralfladen 

 under Kjønsproduktets Udvikling. Tab. 1, Fig. 121. Paa 

 flere af Pinnulerne vare Æg i fast alle Stadier udviklede; paa 

 andre Individer fandtes Testikler, der mikroskopisk havde 

 samme Udseende som Æggestokken. 



Skiven er meget hvælvet, strækker sig op imod 4de 

 Brachiale, naar Armene ere lukkede, og danner da næsten 

 en Konus; med aabne Arme er den muligvis lidt mindre 

 konvex. Tab. I. Fig. 15 a. Den dannes af en temmelig 

 fast Membran, Perisomet, hvori forskjelligtformede, smaa 

 Kalkplader ere leirede. Perisomet gaar over paa Radia- 

 lerne. hvortil det fæster sig, og forlænger sig op langs hele 

 Ventralfuren saavel paa Armene som paa Pinnulerne. 

 Skivens Sider, der kommer tilsyne mellem Armene og 

 den øverste Række Radialer, ere ligesom foldede paalangs, 

 det vil sige, der dannes 5 Længdefolder. som ere de egent- 

 lige 5 Interpalmarfelter, der rage med sin runde, fri Rand 

 udover Munden, og hvori sees en stor, netformig Kalkplade 

 (Oralplade). Under disse 5 Klapper, lidt nedsunket i Pe- 

 risomet, findes lige i Skivens Centrum den runde Mund- 

 aabning. der er omgiven af en ringformig Fordybning, hvori 

 mange Tentakler tåge Plads, Tab. I. Fig. 15 b. Disse 

 Tentakler adskille sig ikke fra de tidligere omtalte, som 

 lindes i Ventralfuren paa Armene og Pinnulerne. De ere 

 alle temmelig lange, cylindriske, forsynede med smaa, koni- 

 ske Papiller, der maaske paa Mundtentaklerne ere noget 

 længere end paa de øvrige og have i Huden enkelte Kalk- 

 spikler. Fra Randen af den ringformige Fure gaa imellem 

 Interpalmarfelterne 5 dybe Længdefurer henimod Skivens 

 Periferi, hvor de dele sig i to, en til hver Arm, Tab. I, 

 Fig. 15 c. Temmelig nær Munden, i et Interpalmarrum, 

 rager Reetum snabelformigt 3—4""" over Skiven, og paa 

 Enden af denne snabelformede Reetum danner Analaabnin- 

 gen en Tverspalte. Tab. I, Fig. 15 d. 



Dr. P. Herbert Carpenter tor vel ansees for den 

 største Autoritet, naar Talen er om Crinoiderue, baade med 

 Hensyn til deres Systematik og anatomiske Bygning. Hans 

 siiiste Arbeide over de paa Challenger Expeditionen ind- 

 samlede Crinoider er klassisk og vil gjennem alle Tider 

 hævde sin Rang. Det er derfor ikke uden en vis Æng- 

 stelse. at jeg rører ved hans Undersøgelser over Slægten 

 Bathycrinus. Imidlertid tror jeg efter fornyede Undersø- 



Den norske Norcllinvsexpedition. D. C. Danielssen: Crinoida. 



towards the groove. They are attacbed to the inner side 

 of the margin that bounds tbe groove, and which is really 

 the boundary of the lateral surfaces inwards. They are 

 seated somewhat altematinglv so that. when they cli.se the 

 groove, the one lies obliquely over the other (Pl. 1. fig. 

 12k). These valves are formed of a tine. beautiful cal- 

 careous reticulation, and are covered with an extremely 

 delieate, almost transparent membrane. which is the con- 

 tinuation of the membrane that covers the arms as well 

 as the pinnules (Pl. figs. 13 c, 14). 



The reproductive organ is found on the 7 lowest pin- 

 nules; it is tenon-shaped, and during the development of 

 the sexual product occupies nearly the entire ventral sur- 

 face (Pl. I, fig. 12 1). Upon several pinnules there were 

 ov.i in almost every stage of development; in other indi- 

 viduals testicles were found which. under the microscope, 

 had the same appearance as the ovary. 



The disc is much arcuated and, when the arm is 

 closed, stretches itself up towards the 4th brachial, and 

 forms then almost a cone; with the arms open it is, possibly. 

 a little less convex (Pl. I, fig. 15 a). It is formed of a pretty 

 finn membrane. the perisome, in which variably formed. 

 small calcareous plates are embedded. The perisome passes 

 over to the radials, to which it attaches itself, and prolongs 

 itself up along the entire ventral groove on the arms 

 as well as on the pinnules. The sides of the disc, which 

 become visible between the arms and the uppermost series 

 of radials, are, as it were, folded longitudinally, that is to 

 say, 5 longitudinal folds are formed, which are the 5 real 

 interpalmar areas that, with their round, free margin pro- 

 ject beyond the mouth and in which a large, reticulate 

 calcareous plate (the oral plate) is seen. Below these 5 

 valves. sunk a little in the perisome, is the round oral 

 aperture, exactly in the centre of the disc; it is surrounded 

 by an annular cavity which is occupied by many tentacles 

 (Pl. I. fig. 15 b). These tentacles do not differ from those 

 previously mentioned as found in the ventral groove on the 

 arms and the pinnules. They are all pretty long and 

 cylindriform, are furnished with small conical papillæ which 

 are, perhaps, a little longer on the oral tentacles than on 

 the others, and they have oecasional calcareous spicules in 

 the integument. From the margin of the annular groove 

 5 deep longitudinal grooves pass between the interpalmar 

 areas towards the periphery of the disc. where they divide 

 into two, one to each arm (Pl. I. fig. 15 e). In one inter- 

 palmar space, pretty near to the mouth, the reetum projects 

 in proboscis-shape 3—4'»™ above the disc, and at the extremitv 

 of this proboscis-shaped reetum the anal aperture forms a 

 transversal fissure (Pl. I. fig. 15 d). 



Dr. P. Herbert Carpenter may. presumably. be regarded 

 as the greatest authority on the subject of the crinoids. 

 both in regard to their system and anatomical structure. 

 His latest work, on the crinoids eollected by the Challenger 

 expedition, is a classical one, which will in all time coming 

 take the highest rank. It is, therefore, not without a certain 

 feeling of trepidation that I touch upon his investjgations 

 • of the genus Bathycrinus. In the meantime I believe. 



