12 



into three orders 1 Tubicoles, Dorsibranches and Abranches using 

 the respiratory organs as the principal distinguishing character. In 

 the Tubicoles the gills are anterior, while in the Dorsibranches they 

 are situated along the sides of the middle part of the body. Cuvier 

 further stated that the genera of the first two orders have bundles of 

 chaetae along their sides, serving as feet ; but some genera of the 

 third order do not possess these. He arranged the genera in their 

 orders thus : 



I. Lea Tubicoles. II. Les Dorsibranches III. Les Abranches. 



Les Serpules. Les Nereides. Les Lombrics. 



Les Sabelles. Les Eunices. Les Thalassemes. 



Les Terebelles. Les Spio. Les Naides. 



Les Amphitrites. Les Aphrodites. Les Sangsues. 



Les Arrosoirs. Les Amphinornes. Les Dragonneaux. 2 



Les Dentales. Les Arenicoles. 

 Les Siliquaires. 



Lamarck 3 (1818) developed the basis of classification. Reused 

 additional morphological characters 4 in subdividing the Annelids 

 into three orders, in which he arranged the genera into families, 

 disposed as shown below : 



Apodes.' Antenn6es.' ; Se"dentaires. 7 



Les Hirudinees. Les Aphrodites. Les Dorsalees (Arenicole, 



Les Echiur^es. Les Nereidees. Siliquaire). 



Lombric. Les Eunices. Les Maldanies (Clyinene, 



Thalasseme. Les Amphinomes. Dentale). 



Cirratule. Les Amphitrites. 



Les Serpulees. 



Savigny 8 adopted practically the same morphological characters 9 

 as aids to classification, but attached primary importance to the 

 presence or absence of chaetae. He formed four orders by grouping 

 the Annelids around four central genera, which gave their names to 



1 Retained in new edition, iii (1830), and in " Edit, de Disc." 



2 Gordius. 



3 Hist. Anim. sans Vert., v, 286. 



4 Probably the introduction of these characters, especially the nature of the 

 chaetae, should be credited to Savigny, who in May 1817 had presented to the 

 Academic des Sciences an account of his researches on the classification of 

 Annelids, and in July of the same year the first part of his classical memoir, 

 which was not published until 1820. 



5 No feet ; no feelers ; respiratory structures, if any, internal, 



6 Definition as under Nereideae of Savigny (see p. 13). 



7 Definition as under Serpuleae of Savigny (see p. 13). 



8 Syst. des Annel. (1820), p. 5. 



9 See footnote (*) above. 



