642 RECORD OF CURRENT RESEARCHES RELATING TO 



more evident than with tlie Ecliiuoidea, 57 per cent, of wliicb are 

 identical in the present time and in tertiary deposits ; the Crustacea, 

 indeed, give a percentage of 67, but we know of only 9 fossil 

 species of this order, whereas 19 Echinoidea have been discovered. 

 6 Foraminifera, 1 Cephalopod, and 1 Brachiopod have been found 

 fossil, and none of these are identical with recent forms. 



Remarkable Ophiurid.* — Herr v. Martens gives a description of 

 a new species, Opldotliela cUvidua, from Algoa Bay. The species was 

 six-rayed, but was remarkable for the fact that in the large number of 

 specimens examined, the arms of each individual were always unequal 

 in size, and that the longer arms all lay on one side of the disk ; 

 there might be three large and three small, or two large and four 

 small arms. It would appear, therefore, that the creature had under- 

 gone transverse division, and that the smaller arms were newly 

 formed. These specimens afford some support to the doctrine on 

 Avhich the author has j^reviously insisted : that when star-fishes have 

 more than five arms, it is, as a rule, in consequence of the animal 

 having budded them off after division or injury. 



Mediterranean Echinoderms. f — In the present essay, Dr. 

 Hubert Ludwig gives a brief account of Antedon pTialangium, and 

 points out the differences between it and A. rosacea ; and of Astropecten 

 squamatus, of which he has been enabled to examine Miiller and 

 Troschel's type-sj)ecimen, and with which he associates Philippi's 

 A. aster. He then describes a new species of the Ophiurida, OpMoconis 

 hrevispina, of which genus as yet only two species were known. In 

 giving an account of Thyone aurantiaca he jioints out that the presence 

 of a male genital papilla appears to be very common among the Deu- 

 drochirotfe ; and he concludes wdth a notice of a Mediterranean species, 

 Holotliuria mammata, which was described by Grube in 1840, and 

 appears to have been never again observed. 



Ccelenterata. 



Intracellular Digestion in Coelenterata.J — Professor Metschnikoff 

 considers that this phenomenon, already demonstrated by Jeffrey 

 Parker in Hydra, must be regarded as the rule in most of the true 

 Coelenterates. It has now been observed in the Hydroids Plunmlaria, 

 Tubularia, the Hydromedusfe Eucope, Oceania, Tiara, as the intrusion 

 into the endoderm cells of solid alimentary particles ; also in Pelagia, 

 Praya, Forsluilia, Hippopodius, in the Ctenoj^horan Beroe, and in the 

 Actinians Sagarfia and Aiptasia ; it has not been noticed in the 

 Trachymedusse. In the Hydroidea and Oceanidfe almost the whole 

 endoderm has this property (in Eucope the genital organs, the wall of the 

 circular vessel, and the base of the tentacles were thus penetrated), but it 

 is usually limited to certain cylindrical thickenings; in the Siphono- 

 phora it is exerted only by the thickenings of the median division of 

 the stomach ; in Actinice the mesenteric filaments must now be 



* ' SB. Ges. Natnrf. Freund. Berlin,' 1879, p. 127. 

 t 'Mitth. Zool. Stat. Neapel,' ii. (18S0) p. 53. 

 X ' Zool. Anzeig.,' iii. (1880) p. 261. 



