TEREBELLIDtE. 101 



Malmgren; under Potymnia, Terebella and Polymnia, Malmgren; under 

 Leoena, both that genus and Lanassa, Malmgren, and included under Thelepus 

 both Neottis and Grymoea, Malmgren. 



Finally he arranges the Mediterranean forms thus : 



A. Bristles with the end flattened and serrated. 



I. Bristle-tufts in seventeen to twenty-four segments, appendage to the bristles — 

 Amphitrite. 

 II. Bristle-tufts on all the segments from the fourth, the tip short, slightly curved. 



B. Bristles with simple tips. 



I. Seventeen setigerous processes beginning at the fourth. Hook-rows double 



from the eleventh to the twentieth. Ex. Lanice, Pista, Polymnia. 

 II. Seventeen setigerous processes beginning at the third segment. Hook-rows 

 single — Thelepus. 



The careful descriptions of the species and the reliable figures make this paper 

 valuable to all students of the group. 



Meyer 1 (1886) contributes many important features in the structure of the 

 Terebellids, such as the nephridia, the circulation and the heart-body, and his paper 

 is illustrated by excellent drawings. Amongst the forms specially treated are Amphitrite 

 rubra, Polymnia nebulosa, Lanice conchilega and Loimia medusa. 



Cuenot 2 (1891) deals with the lymphatic glands, amoebocytes, blood (haematines), 

 the development of the genital organs and other features of invertebrates, including 

 the Polycha3ta. Special remarks are made on Polycirrus hsematodes, Leprsea lapidaria, 

 Spirographs spallamtani, Nicolea venustida, and Myxicola infandibtdum. 



After an elaborate consideration of the grounds on which previous classifications of 

 the Terebelliclae were based, and the difficulties which had been encountered, De St. Joseph 

 (1894) promulgated a new classification, having for its basis the arrangement of the 

 hooks in the rows, the condition of the branchiae, the structure of the hooks and bristles 

 and other features. The main divisions are as follow : 



I. Transverse rows of denticles on the vertex of the avicular hooks. 



a. Branchiae absent. 



(a) Hooks with a short base and elevated crest with a large number of teeth 



(seven to eleven), three transverse rows of teeth. 



(a) Hook with a posterior prolongation — Pherca, n.g. (b) Without 

 a posterior prolongation — Bathya, n. g. and Proclea, n.g. 



(b) Base of the hooks long, and the vertex relatively little elevated. Bristles 



commencing on the fourth segment — Leoena, Mgrn., with bristles of one 

 kind, and Phisidia with bristles of two kinds. Bristles commencing on 

 the third segment — Laphania, Mgrn. 



b. Branchiae ramose, cirriform or rarely subulate. 



1. Bristles commencing on the fourth segment and with serrated points ; hooks 

 with six rows of denticles ; numerous setigerous segments — Amphitrite, 

 0. F. M. Three to four rows of denticles— Terebella, L. 



1 ' Mitt. Zool. St. Neap./ Bd. vii, pp. 592—748, Taf. xxii— xxvii. 



2 c Archiv Zool. Exper./ 2 e ser., t. ix. 



