572 Chronicles of Science. [Oct., 



of Naples,' and he now appears again, first with an essay — written 

 in German this time (he writes equally weU in that language or in 

 French) — entitled ' Studies on Acarids,' illustrated with eleven 

 coloured folding plates ; and secondly, with a joint paper in asso- 

 ciation with Professor Elias Mecznikow ' On the Development of 

 Chsetopodous Annelids,' illustrated with six coloured plates ; besides 

 these, he has in the press an extensive memoir ' On the Anatomy 

 of the Earthworm.' Nothing could more clearly show the im- 

 portance to the naturalist of possessing skill with the pencil than 

 these beautiful labours of Professor Claparede. He is able rapidly 

 to note down his observations by this means, and the very same 

 faculty which enables a man to draw what he sees, makes him, at 

 the same time, more apt at disentangling the intricacies of a struc- 

 ture, and more rapid and certain in his observation altogether. The 

 ' Studies on Acarids ' is perhaps the more important of the two 

 works we have mentioned, since the development of several species 

 is accurately and carefully detailed and figured ; whilst the anatomy 

 of several others is given, and some remarks headed " Fiir Darwin" 

 are appended, pointing out certain arguments in favour of natural 

 selection and descent which may be gathered from this group, as 

 Fritz Miiller has so well gathered from the Crustacea. 



A Living Cystidean. — The Cystidea are a very peculiar group 

 of Echinoderms whose remains are abundant in the carboniferous 

 and other Palasozoic rocks, and they have always been supposed to 

 have become extinct before Mesozoic times. The sensations, there- 

 fore, evoked by the announcement of a living Cystidean may be 

 well described as unusual. Yet I'rofessor Loven calmly describes 

 in a paper only just published, an Echinoderm which he received 

 from Cape York, and which appears to justify his assertion that it 

 is a living Cystidean. In some features it agrees with the living 

 crinoid Comatula, but in the fact that the canal between the ambu- 

 lacral organs is covered in by calcareous plates, it agrees with the 

 Cystidea alone. Further details and figures of this form are 

 anxiously expected. Professor Loven terms it Hyponome. It is 

 worth mentioning, in connection with this, that at the depth of 

 more than a thousand fathoms. Professor Wyville Thomson has, 

 during the last month, dredged aii Echinoderm, which he says 

 must be regarded as the type of a totally new division of that 

 group. For an account of his exceedingly interesting letter to 

 Rev. Alfred Norman, read to Section D of the British Association, 

 we must refer the reader to our Report. 



Fresh-water Radiolarians. — Tlio beautiful group, some forms 

 of which are known to us as Fohjcydina in Barbadoes earth, which 

 have been so wonderfully worked out by Ernst Ha'ckel, in his 

 'Monograph of Radiolaria,' which comprises the llialassicolla of 

 Huxley, and the Acanthometra of Miiller, and the members of which 



