144 SYLLID-ZE. 



He makes four great tribes : 



« ir -j .,, Li C throughout . Exogones. 



Sylhd* with | pal t ) fused . . { at the bage onl Bus llid& . 



ventral cirrus ) 1 o. -.-..-,, 



(..separate Sylhdes. 



Palps absent . Autolytes. 



He gives an elaborate list of the genera under each tribe, with careful references, 

 and a few remarks. 



This author 1 maintains that the cephalic lobe in the Syllidse and other forms is 

 homologous with the ordinary segments of the annelid; thus the lateral tentacles 

 correspond to the ventral division ; the median to the dorsal cirri ; the palps to the 

 ventral cirri, and the tentacular cirri (anterieures, laterales, posterieures) to the dorsal 

 division. This is contrary to the views of his countryman, Pruvot, who holds that the 

 cephalic region consists of three segments with three corresponding nerve-centres : 

 (1) The stomatogastric with its appendages the palps; (2) the tentacular segment 

 (segment antennaire anterieur) with the lateral tentacles ; (3) the posterior tentacular, 

 with the median tentacle (composed of two fused). Of the two views Malaquin's has 

 most in its favour. 



Malaquin 2 (1893) found the pharyngeal wall to have in Syllis ; 



(1) A thick layer of chitine. 



(2) An epithelium secreting the foregoing. 



(3) A thin layer of circular muscles. 



(4) A thick longitudinal muscular coat. 



(5) A layer of peritoneal endothelium. 



The proboscis has protractor and retractor muscles. 



In the case of the proventriculus, he describes from without inwards : 



(1) The peritoneal endothelium. 



(2) Thin external circular muscular coat. 



(3) Complex radiating muscles separated by transverse diaphragms. 



(4) Internal circular muscular coat. 



(5) Columnar epithelium of the digestive tube. 



(6) The cuticle. 



The ventricule (stomach) follows, and often presents T-shaped lateral caeca, which 

 have the same ciliated epithelium as the ventricule. Malaquin thinks they are filled 

 with water pumped in by the proventriculus. In those without these organs, the author 

 considers that the anterior part of the intestine performs their function. He divides the 

 intestine into the glandular secreting anterior, and the rectal or urinary posterior. 



He uses the terms " schizogamy " and "epigamy " to distinguish the reproductive 

 processes in the Syllidee. 



The former (" schizogamy ") is applied to cases in which a non-sexual nurse-stock 

 gives off sexual buds. In the latter (" epigamy ") the individual is entirely sexual. 

 Epigamy (Malaquin) is accompanied by the enlargement of the eyes and the elongation 



1 ( Recherches sur les Syllidiens/ Lille, 1893, p. 487. 



2 Op. cit, p. 194. 



