10 



geiser at kunne konstatere Rigtigheden af de af mig tid- 

 ligere beskrevne Syzygier, saavel raellem Iste og 2det Ra- 

 diale som imellem Iste og 2det Brachiale samt imellem 

 4de og 5te og saa fremdeles. Dr. Carpenter siger med 

 Hensyn hertil: „To the kindness of Dr. Danielssen I have 

 been able to satisfy myself that these ..syzygial unions-' in 

 the arms of Bathycrinus carpenteri are really trifacial arti- 

 culations like that between the two outer radials of Bathy- 

 crinus aldrichianus. If, however, this term be substituted 

 for syzygy in the description by Danielssen and Koren, 

 their statements respecting the grouping of the braehials 

 would be perfectly correct, i. e. in the nine lowest braehials 

 there are alternations of a pair ot joints united by trifacial 

 articulations and a single joint with muscular articulations 

 at both ends. Beyond the ninth brachial the two forms 

 of articulation alternate with great regularity. Apart from 

 the question of nomenelature, therefore, the Norwegian 

 naturalists were the first who correctly described the 

 grouping of the joints in the arms of Bathycrinus: for I 

 ti iid that their description of Bathycrinus carpenteri. applies 

 both to the little Bathycrinus gracilis dredged by the 

 Borcupine and to the two Challenger species, Bathycrinus 

 aldrichianus and Bathycrinus campbellianus. The non-sy- 

 zvgial nature of the paired unions in the arms of the two 

 last has been determined by actual investigation of the joint 

 faces; while careful microscopic examination of the small 

 individual of Bathycrinus gracilis has convinced me that it 

 resembles the other three species in this respect". 



Dr. Carpenter har med Hensyn til Leddene saavel i 

 Radialerne som i Armene hos Bathycrinus Carpenteri baade 

 Ret og Uret. Det forholder sig ganske rigtig saa. at hos 

 unge Individer er der virkelig de af ham paaviste Artiku- 

 lationer og ikke, som jeg har beskrevet, Syzygier. ja hos 

 ganske unge Individer er der ikke engang den mindste 

 Antydning til Syzygier: men anderledes forholder det sig 

 med gamle Individer, hos dem er nemlig de af Carpenter 

 beskrevne „trifacial articulations" fuldstændigt anchyloserede 

 og danne sande Syzygier. hvori ingen Bevægelse tindes. 

 Muskulaturen er ogsaa her saagodtsom ganske atrofieret, 

 medens den hos de unge Dyr er i fuld Vigor. 



Forbindelsen (Suturen) imellem de første Radialer og 

 Basalerne er meget løsere end mellem disse og det oveiste 

 Stamled, hvorfor Kronen temmelig let løsrives fra Stilken 

 saaledes, at Basalerne sidde igjen paa denne. Dette For- 

 hold synes at være Tilfældet med flere stilkede Crinoider; 

 saaledes viste det sig, at af de to Exemplarer af Bathycri- 

 nus gracilis, der i 1869 blev fundet paa Porcupine-Expedi- 

 tionen, var det enes Krone løsrevet paa den omtalte Maade, 

 og af Bathycrinus campbellianus, hvoraf kun en Krone er 

 kjendt, viser denne sig at være skilt fra Stilken med Basa- 

 lerne. Men det mrerkeligste i dette Tilfælde indtraf dog 

 ved Station 146 i det stille Ocean, hvor Skraben man, 

 have gaaet over en lille Skov af Bathycrinus aldrichianus. 

 Dr. Carpenter meddeler med Hensyn hertil: ,.About a dozen 

 tolerably perfect individuals were obtained, together with 

 a considerable number of stems retaining the basal ring 



after renewed investigations, that I am able to confirm the 

 correetness of the syzygia previously described by me, both . 

 between the Ist and 2nd radials as well as between the 

 Ist and 2nd braehials. also between the 4th and 5th, and 

 so onwards. Dr. Carpenter says with regard to this : 

 ,.To the kindness of Dr. Danielssen I have been able to 

 satisfy myself that these ..syzygial unions-' in the arms of 

 Bathycrinus carpenteri are really trifacial articulations like 

 that between the two outer radials of Bathycrinus aldri- 

 chianus. If. however, this term be substituted for syzygy 

 in the description by Danielssen and Koren, their state- 

 ments respecting the grouping of the braehials would be 

 perfectly correct, i. e. in the nine lowest braehials there 

 are alternations of a pair of joints united by trifacial 

 articulations and a single joint with muscular articulations 

 at both ends. Beyond the ninth brachial the two forms 

 of articulation lalternate with great regularity. Apart from 

 the question of nomenelature. therefore, the Norwegian 

 naturalists were the first who correctly described the 

 grouping ot the joints in the anns of Bathycrinus; for I 

 find that their description of Bathycrinus carpenteri applies 

 both to the little Bathycrinus gracilis dredged by the 

 Poivupine aud to the two Challenger species. Bathycrinus 

 aldrichianus and Bathycrinus campbellianus. The non-sy- 

 zygial nature of the paired unions in the arms of the two 

 last has been determined by actual investigation of the joint 

 faces; while careful microscopic examination of the small 

 individual of Bathycrinus gracilis has convinced me that it 

 resembles the other three species in this respect - '. 



Dr. Carpenter is, in regard to the joints, in the 

 radials as well as in the arms of Bathycrinus carpenteri, 

 both right and wrong. It is quite the case that in young 

 individuals there are really the articulations he has shown, 

 and not syzygia as I have described; indeed in perfectly 

 young individuals there is not even the least indication of 

 syzygia, but it is different in the case of old individuals; 

 in tliem the ..trifacial articulations" described by Carpenter 

 are completely anchylosed. and form real syzygia in which 

 no mobility exists. The nmsculosity is here, also, almost 

 perfectly atrophied. while in young animals it is in full 

 vigour. 



The connection (the suture) between the first radials 

 and the basals is much looser than between these and the 

 uppermost stalk-joint, so that the crown permits itself to 

 be easily detached from the stalk in such a manner that 

 the basals are left bebind. That relation seems to be the 

 case in several stalked crinoids: it thus appeared, that of 

 the two specimens of Bathycrinus gracilis which were found 

 on the Porcupine expedition in 1869. the crown of the one 

 was detached in the manner spoken of, and Bathycrinus 

 campbellianus. of which only one crown is known, shows 

 the crown to have been separated from the stalk at the 

 basals. But the most remarkable circumstance in that 

 relation took place at station 146. in the Pacific Ocean, 

 where the dredge must have passed over a small forest of 

 Bathycrinus aldrichianus. Dr. Carpenter states in regard 

 to this: ,.About a dozen tolerably perfect individuals were 



