18 Catalogue of Chaetopoda 



IV. Oligochaeta — Annelids in which the lateral locomotor organs 

 consist of two to eight bristles projecting from scarcely recognisable 

 elevations and not accompanied by cirri, " Lippenblatter " or gills ; 

 the genital organs are hermaphrodite, paired, and limited to a few 

 segments ; the majority of these worms live in the earth or in fresh 

 water, only a few are found in the sea. 



V. Discophora, corresponding to the Hirudineae of earlier 

 systematists. 



The Polychaeta were divided into two sub-orders — Eapacia and 

 Limivora — according to the mode of feeding ; but, as Grube carefully 

 pointed out, the members of the two sub-orders differ in many of 

 their structural characters. The families of Polychaeta were arranged 

 thus :— - 



B. Limivora. 



Opheliacea. Maldania. 



Pherusea. Terebellacea. 



Chaetopterea. Hermellacea. 



Telethusa. Serpulacea. 



In the years 1865, 1866 there appeared three works on Annelids. 

 In 1865 Johnston's " Catalogue of Non-parasitical worms in the 

 British Museum " was issued, in which these worms were arranged 

 in six orders, as follow : — 



A. — Apodous : the body without bristles on the sides. 



1. Body exannular. 



I Order. Turbellaria.^ 

 II Order. Bdellomorpha.^ 

 V Order. Gymnocopa. 



2. Body annular. 



III Order. Bdellidea. 



B. — Polypodous : the body with bristles along the sides. 



IV Order. Scoloces. Without external soft appendages ; the segments 



with simple spiniform or setaceous bristles, either 

 single or fasciculate. 

 VI Order. Annelides. AVith soft external appendages, and with 

 various bristles collected into fascicles on a more or 

 less protuberant basis. 



The Annelides were divided into Eapacia and Limivora, in which 

 tribes the families were arranged as in Grube's classification. The 

 use of the term Annelides for a subdivision which did not include 



^ Included animals now referred to the Turbellaria and Nemertea. 

 - Included the genera Octohothrium, Entobdella, Malacobdella, etc. 



