222 



of Ihe larva. Tlu' crossed pedicdlaritp. present in bolh larval slages, de- 

 (inilely prove Ihal il belongs lo Ihe suborder oi' the Forcipuiala, and rea- 

 sons are f*iven for the suii;gestion liial il is the larxa of a deep-sea form. 

 It is a noticeable fad tiial no traces of a \ibralile liand aie found. 



riiiounh Ihc kindness of Professoi" .liilcs iiichiinl I haxc iccciNt'd 

 from llie Musee Oceanographique of Monaco some s|)ecimcns of this very 

 interesting larva. The examination of these specimens has led me to an 

 interpretation differing rather considerably from that given by Koehler 

 iS[ Vaney. Hoth the stages described are far advanced metamorphosis 

 stages, so that the true shape of the larva is not to be made out, the larval 

 body most ])robably ( — as may be inferred fiom a comparison with the 

 later metamorphosis-stages of Asteiias — ) alreail\- being foi- [he greater 

 part absorbed. But this mucii is still clear. Ilia I the larva belongs lo the 

 Brachiolaria-type. In fact, llicre can be no doubl that what Koehler iV 

 Vaney Lake lo be the moulh of the larva is really the sucking disk of the 

 Hrachiolaria, round which are found the three typical Brachiolarian arms. 

 They arc ol ([uilc typical shape, ca. 2 — 5 mm long, cylindrical, the point 

 being covered wilii small papilhe; furthermoic there is a close series of 

 similar small papilhe from the base of the median, anterior Brachiolarian 

 arm backwards lo each side of the sucking disk. On the larval body there 

 are besides found the last vestiges of the othei- larval arms, mostly reduced 

 to mere papilliform processes, which can no longer be identified with 

 certainty, excepting only the unpaired, median dorsal process, situated 

 behind the median B.rachiolarian arm. The larva is in a stage correspond- 

 ing very closely with that represented in PI. 21, Fig. 13 of (iemmill's 

 Memoir on the development of Aslerias rubens^). If only the body and 

 arms were a lilLle more contracted — as they would ceiLainly be on a 

 not very careful preservation — we would here have a figure very well 

 representing the Siellospha'ia. If we now look upon the figures on I'l. 

 XXIV of Koehler' s work, it is evident that the figure 10 represents a 

 larva seen from the apical pole, showing the sucking disk in the middle, 

 with the three Brachiolarian arms (very poorly represented they have 

 evidently been unusually conliacted in that specimen; the paj)illa* on the 

 point of the.se "pedicelles jjeribuccaux" were also observed by Koehler 

 & Vaney). The smaller papilla* scattered over the body are the remnanls 

 of the larval arms, nol at all the beginning lubefeet of the young starfish, 

 as would seein to be the opinion of the authors. The six large calcareous 

 plates with the clusters of spines are the terminal plates of the starfish. 

 Another curious result of this examination is that the I. stage of Koehler 

 & Vaney is really the oldei-, more advanced stage, their II. stage being 



') I'Jiil. Trans. Ser. B. Vol. 205, 1914. 



