Report on the zoological collections made in the Indo-Pacific Ocean ...

ECHINODEKMATA. 167A specimen "with an arm 120 millim. long has the cirri 15-5millim. lone:, the first pinnule 20 millim. long, and the arms 3 millim.at their widest ; in other words, these measurements are very muchthe same as those of the specimens of A. Solaris lately referred to.The faint white line which is so often seen along the middle of thedorsal surface of the arms is to he seen in some specimens ; and insome cases we may observe the black spots on the pinnules, towhich attention has already been directed.It will be clear enough to the student that the specimens now underdiscussion present several points of considerable difficulty ; but, thoi;ghthey have the general facies of ^. Solaris and on the other hand alarger number of cirri and a feebler keel, thereby approachingA. robusta, thej% at the same time, present sufficient constancy inthe retention of their differential characters to prevent our believingthat the differences that we observe have not passed Avithin the influenceof the laws of heredity.Albany Island.18. Actinometra robusta.Actinometra robusta (Zilfken, MSS.), P. H. Carpente?-, Journ. Linn.Soc, Zool. xvi. p. 517.In specimens of this comparatively well-marked form from " St.144," * which were somewhat smaller than those described byMr. Carpenter, I noted that the basal joints of the arm were not sodistinctly knobbed, and that there was a faint carination to the basaljoints of the second pinnule. On the other hand, in a larger specimenfrom Port Curtis, which appeared to be particularly well developed,the knobs were very prominent."With regard to the specimens from St. 144, Dr. Coppinger notesthat they were " originally of a purple colour."19. Actinometra strota.Among the present collection of Crinoids Mr. Carpenter recognizeda single specimen of a species which he has distinguished asA. stroia, n. sp., and of which he will give a full account in hisforthcoming <strong>Report</strong> on the Comatulce of the 'Challenger' Expedition.Port MoUe.20. Actinometra cumingii.Comatula cumingii, /. Miiller, p. 19.A delicate specimen with 10 cirri, the cirri having about 12joints and no penultimate spine, and most of the joints being a* Probably Thursday Jsland.