221 



Asteroids no breaking up and subsequent rearrangement of the ciliated 

 band into transverse rings has been observed, such as it occurs especially 

 in Holothurians, but also, more or less distinctly, in Ophiuroids and Echi- 

 noids; accordingly we cannot speak of a pupa-stage in Asteroids 

 corresponding to that of Holothurians and (more or less modified) of 

 Ophiuroids and Echinoids. Neither do the forms with direct development 

 (Henricia, Solaster etc.) develop cihated rings, as do the Crinoids and 

 Holothurians with abbreviated or direct development; there is only a 

 general ciliation in these reduced starfish-larvae. It is, of course, possible 

 that larvae with cihated rings may occur among those of the Phanerozonia 

 which have direct development; but as yet we do not know a single case 

 of such larvae within the Asteroids — and this fact is not in favour of the 

 suggestion that the simple, wormshaped larva provided with ciliated rings, 

 hke the Comatulid- and the Dendrochirote-larvae, represents the primitive 

 Echinoderm-larva. 



Two more forms of starfish-larvae have been described, which would 

 appear to represent special types differing essentially from the main types 

 treated above. They must be briefly mentioned here. 



In my Memoir on "Die Echinodermenlarven d. deutschen Siidpolar- 

 Expedition" '^) p. 89 notice is given of a larva with more than 20 Brachio- 

 larian processes, the general shape of the larva being otherwise like that 

 of a typical Asterias-larva ; the larva itself I had not examined, the descrip- 

 tion being founded on observations of the living specimen made by Van- 

 hoffen during the stay of that Expedition in the Antarctic Sea. As later 

 on the specimen of this larva was examined by me, those numerous Bra- 

 chiolarian arms were found to be a mistake; they were nothing but the 

 spines of the young metamorphosing starfish. — A correction of the de- 

 scription was given in the "Vorwort" to the said volume of the "Deutsche 

 Sudpolar-Expedition", p. VI; but as this correction is very likely to be 

 overlooked I have found it my duty to mention it here. 



In 1906 Koehler & Vaney^) published the description of a remark- 

 able new Asteroid-larva, taken in the vicinity of the Azores, which was 

 named Stellosphaera mirabilis. Only two stages were observed, the younger 

 being provided with clusters of large spines, which were absent in the later 

 stage, so that a remarkable, regressive development of the calcareous 

 bodies in the larval skin takes place during the progressing development 



1) Deutsche Sudpolar-Expedition 1901—1903. Bd. XIV. Zoologie VI. 1913. 



2) R. Koehler et Cl. Vaney. Description d'une nouvelle larve d'Asterie appartenant 

 tres vraisemblablement a une forme abyssale. Bull. Mus. Oc6anogr. Monaco. No. 64. 1906. 



The description was reprinted in Koehler's great work "fichinodermes provenant des 

 campagnes du yacht Princesse Alice (Asteries, Ophiures, fichinides et Crinoides), R6s. d. 

 Camp. Scient. Monaco. Fasc. XXXIV. 1909. p. 131—136. PL XXIV. 



