BRITISH ANNELIDS. 509 



be synonyms of Tristoma (and all of whicli belong to the Trematodes) 

 and MalacoMella ; whicli latter, while showing certain affinities in its 

 development to the Trematodes, is, perhaps, better placed at the end 

 of the Diseophora. The third Order is that of the Bdellidea, which 

 is synonymous with the Diseophora of Grube. This, and the next 

 order, that of the Oligochaeta, are now almost universally regarded 

 as sub-orders of the Annulata. Here we have the various species 

 of Fontobdella, Hiricdo, and GlossipTionia, and in the appendix 

 there are more copious details, and, in some cases, better descrip- 

 tions than in the text. In the list of the British genera we notice 

 the following instances of incorrect spelling : TrocTieta for Troclietia, 

 Scemopsis for Ecemopis, Glossophonia for GlossipJionia. Doubtless, 

 further investigations will not only add many species to the genus 

 GlossipJionia, but will also assign many of the present species as 

 varieties of others. In the account of the Oligochseta, there are 

 many interesting details as to the habits and economy of the earth 

 worms. The old controversy, as to the power of the common worm 

 to reproduce lost parts is here renewed, and one can now look at 

 the subject from a more impartial point of view than it was possible 

 to do some fourteen years ago. Villa is the name of a new genus 

 made for the reception of the Lumbricus ciliatus of Miiller, which would 

 appear to differ from Lumbricus in having the segments armed with 

 setaceous bristles in four fascicles. According to Dalyell, it is con- 

 stantly found lurking in the sand of the shore at about half-tide, from 

 whence the head is protruded, waving to and fro. Grube is followed 

 in placing Tomopteris in an order by itself, Gymnocopa. We are 

 inclined to think Tomopteris founded on immature forms ; but this 

 question cannot be settled until something is known about its modes 

 and forms of reproduction. No reference is made in the addenda to 

 the various papers by Carpenter, Claparede, Fagenstecher, and others, 

 on this genus. 



"We now come to the larger and more important portion of this 

 work ; the section which treats of the Annelida, the *' Annulata 

 appendiculata polychseta " of Grube. An introduction of five pages 

 treats of the various terms used in describing the genera and species. 

 Eut these terms are, for the most part, very loose and inexact, 

 whence one of the difficulties of this portion of descriptive Zoology 

 has, we think, arisen. For example, what is an Antenna? what a 

 Palpus ? what a Tentaculum ? how do these all differ from Cirri ? 

 and what are the so-called foot and its bristles, branches, and cirri ? 



