200 Royal Society : — 



In the last section, on " The zoological position and affinities of 

 the Nematoids," the author enters fully into what he believes to be 

 the points of resemblance between these animals and the Echino- 

 derms. The strongest evidence is, he thinks, to be found in the fact 

 of the very close resemblance between the nervous systems of these 

 animals, differing notably as they do at the same time from what we 

 find in the Scolecida or Annelida. Then the integumental pores 

 which he has now discovered in so many Nematoids can, he thinks, 

 be paralleled only by the ambulacral and other pores met with in 

 the Echinoderms. Great similarities in the distribution of these 

 pores may also be observed in the two groups. The Nematoids 

 present no trace of segmentation or lateral appendages to their bodies, 

 but traces of a radiate structure do exist. Their various parts and 

 organs exhibit a quadrate mixed with a ternate type of development. 

 He looks upon the order Nematoidea as an aberrant division of the 

 class Echinodermata, which at the same time tends to connect this 

 class in the most interesting manner with the Scolecida — since, 

 although in the points above mentioned they display their affinities 

 to the Echinoderms, still, as regards the structure and different 

 modifications of the ventral excretory apparatus, they agree more 

 closely with the Trematoda or flukes. 



" Researches on the Structure, Physiology, and Development of 

 Antedon {Comatula, Lamk.) rosaceus." By Dr. W. B. Carpenter, 

 F.R.S. 



The author, after adverting to the special interest attaching to the 

 study of this typical form, as the only one readily accessible for the 

 elucidation of the life-history of the Crinoidea, states it to be his 

 object to give as complete an account as his prolonged study of it 

 enables him to offer, of its minute structure, living actions, and 

 developmental history, taking up the last at the point to which it 

 has been brought in the memoir of Prof. Wyville Thomson. 



He prefaces his memoir with an historical summary of the progress 

 of our knowledge of the distinctive peculiarities of this genus, and of 

 its relation to the Crinoidea; and he shows that the first recognition 

 of this relationship was most distinctly made by Llhuyd, at the 

 beginning of the last century, though that recognition has been 

 passed without notice by most subsequent writers, and is altogether 

 ignored by MM. de Koninck and le Hon in their recent history. 



The author then proceeds to describe the external characters of 

 Antedon rosaceus; and shows, from its habits as observed in a 

 vivarium, that although possessed of locomotive power, it makes so 

 little use of this under ordinary circumstances, that its life in the 

 adult condition, no less than in its earlier stage, is essentially that of 

 a pedunculate Crinoid. 



He then gives a minute description of the several pieces of the 

 skeleton — the accounts of these previously given by J. S. Miller 

 and Prof. Joh. Miiller not being in sufficient detail to serve as 

 standards of comparison to which the parts of fossil Crinoids may be 



