88 ANNELIDA. 



vertebres." For the generic characters I have also 

 been indebted to Messrs. Audouin and M.-Edwards's | 

 " Littoral de la France/' to M. Moquin-Tandon's 

 " Monographic des Hirudinees," and to the nume- 

 rous papers of Dr. George Johnston in various 

 zoological periodicals. In the enumeration of 

 British species I have principally depended on the 

 "Index to the British Annelides " of the last- 

 named gentleman, a work which in small space 

 exhibits the concentrated result of immense re- 

 search and labour, the additions made to the Irish 

 Fauna by Mr. W. Thompson, the contributions 

 of Mr. Goodsir, and Professor Allman, and my 

 own personal researches. It is understood that 

 Dr. Johnston is about to bring out a work on the 

 British ANNELIDA, which is anxiously looked for 

 to dispel the obscurity and confusion which con- 

 fessedly rest on this, perhaps more than on any 

 other department of our native zoology. 



ANNELIDA. 



Body lengthened, soft, divided into numerous 

 ring-like segments; without jointed limbs; with 

 an orifice at each extremity of the alimentary 

 canal; blood generally red, circulating in a closed 

 system of arteries and veins ; skin not clothed with 

 cilia, except on the breathing organs. Distinct 

 sexes. 



Without bristles, or foot-like warts. Loco- 

 motion performed by means of sucking disks Apoda. 



With bristles serving for locomotion, and 

 generally carried on foot-like warts, which 

 are furnished with various appendages . . Chcetopoda. 



