Bibliographical Notices. 



501 



Kingd. Zoophytes, pi. 8.). — Al. europaa, Leach (Com. mediterannea, 

 Lam., Heusinger Zeitschrift f. Physik, iii. tab. 10, 11.). — Al. Adeonce, 

 Mull. (Com. Adonse, Lam., Blainv. ActinoL, tab. xxvi.). — Al. Solaris, 

 Mull. (Com. Solaris, Lam.). — Al. brachiolata, Mull. (Com. brachio- 

 lata, Lam.). — Al. Milleri, Mull. (Com. fimbriata, Mill.) has never 

 again been observed. 



The following new species with 10 arms are then described : — 

 Alecto phalangium, from Nice ; Al. Eschrichtii, from Greenland ; AL 

 echinoptera, locality ? ; Al. rosea, locality unknown ; Al. tessellata, 

 India; and Al. polyarthra. 



** Species with greater division of rays. 

 Alecto rotalaria (Com. rotalaria, Lam.), with 20 — 22 arms ; AL 

 fimbriata (Com. fimbriata, Lam.), with 20 arms; Al. multifida (Com. 

 multiradiata,iam.),with 44 arms ; Al. Savignii (Description d'Egypte, 

 Echinodermes, pi. 1. f. 1.), with 20 arms ; and as new : Al. palmata 

 (? Caput medusae cinereum, Linck, tab. 22, No. 33.), about 35 arms, 

 India; Al. parvicirra, 27 arms, locality?; Al. timorensis, 36 — 40 

 arms, from Timor; AL japonica, 27 arms, Japan ; Al. fiagellata, 38 

 arms, locality ? ; Al. Nova Guinea, 56 arms ; Al. elongata, 20 arms, 

 New Guinea; Al. Bennetti, above 70 arms, locality?. 



The madreporal plate is wanting in the Comatula, and seems to be 

 generally absent in the Crinoidea. Prof. M idler considers the madre- 

 poral plate on Comatula Adeonce figured and described by DelleChiaje to 

 be the Epizoon of the Comatula first noticed by Thompson — a discoid 

 animal with fringed margin. It has anteriorly a snout proceeding from 

 the ventral side, a ramified intestinal canal, and 10 rudiments of feet 

 provided with three long hooks on the ventral side, Cyclocirra Thomp- 

 soni, Mull. It is frequently met with affixed to the disc and arms of 

 Alecto europaa. It differs very considerably from the parasitic worms 

 by its rapid motion without any contraction of the body, and is there- 

 fore more related to the Crustacea, among which however there is no 

 form similar to it. In some measure it appears allied to Arctison, 

 which have not the least relationship to the Rotatoria. 



I have frequently had occasion, says the author, to examine Coma- 

 tula in a live state, and have found the fact to be confirmed, that the 

 cirrhi of the central head are without all motion, as was evident from 

 the anatomy. The arms have a lively motion during swimming, five 

 of the ten arms move alternately at the same time, so that one be- 

 tween each two is in a state of rest. The separation of the sexes was 

 also proved by the presence of Spermatozoa in the male and ova in 

 female individuals in the protuberances of the pinnulse. 



On the organs of hearing in Mollusca, by Prof. C. Th. von Siebold, 

 p. 148 — 168, with a plate. In this interesting paper the author first 

 describes the auditory organs as hitherto observed in the lower tribes, 

 e. g. the Cephalopods, and then proceeds to a description of the cen- 

 tral system of nerves of the Gasteropods, the knowledge of which is 

 requisite for discovering these organs, they being situated in all Gas- 

 teropods on the hinder extremity of the two large front ganglionic 

 protuberances. They must always be sought for near the front pair 

 of ganglions of this portion of the nerves, where they are more easily 



