Report on the Echinoderms of North-East Greenland. 283 



in the young specimens, in accordance with the more or less total 

 disappearance of the calcareous ring in the grown specimens. 



26. Phyllophorus pellucidus, \ar. Barthii (Troschel). 

 PI. XVII. Fig.s. 3-7. 



Orcula Barthii Lütken 1857. Grønlands Echinod. p. 9. 



— — Duncan & Sladen. 1881. Mem. Ech. i\rctic Sea. p. 8. 



Phyllophorus pellucidus (Fleming), varietas Barthii (Troschel). Kali- 



schewskij. 1907. Echinodermen-Fauna d. 



Sibir. Eismeeres, p. 5. Taf. I. Fig. 4 a — e. 



Stat. 63. Stormbugt, 10 — 20 m. 1 specimen, measuring 8 mm, to 

 the base of the tentacles. 



That the "genera" Orcula and Thyonidium cannot be kept 

 distinct from Phyllophorus I quite agree with Dr. Ostergren. The 

 question of the northern Atlantic species: Avhether we may disting- 

 uish 3 species (pellucidus, Drummondi and Barthii), or whether it is 

 altogether one species, needs further examination on a rich, well 

 preserved material. I cannot here enter on such a study, especially as 

 I have not sufficient material available, so I must content myself with 

 giving some remarks on the specimen in hand, naming it prelimi- 

 narily, as does Ka lisch e WS к i j, Phyllophorus pellucidus, \ar. Barthii. 



The tentacles, which are rather w^ell extended, are 15, viz. an 

 outer circle of 10 larger and an inner circle of 5 small ones. The 

 tubefeet are arranged in 5 nearly regular, double rows, equally 

 developed. No tubefeet have appeared in the interradia as yet. 

 The skin contains numerous plates of the form typical in Phyllo- 

 phorus (PI. XVII. Figs. 3—6). The plate of the sucking disk (PI. XVII. 

 Fig. 7) differs somewhat from that of the grown specimens; the dif- 

 ference is due, probably, only to the age. 



For the question about the northern Phyllophorus-species it will 

 be of some value to notice that in typical specimens of '^Orcula 

 Barthii" I find numerous spicules in the skin of the hindmost part 

 of the bod} ; they are of the shape typical for Phyllophorus, but 

 otherwise I find them more or less dissolved so that it is impos- 

 sible to see exactly how their shape has been in all minor details. 

 Another noteworthy fact is that there is in the collection of the 

 Copenhagen Museum at least one specimen of the true Phyllophorus 

 pellucidus from West Greenland (Sukkertoppen), with the skin full 

 of the typical calcareous corpuscles. The number of tentacles of 

 this specimen cannot be ascertained, as the whole anterior end of 

 the animal is lacking. 



