DESCRIPTIONS OF GENERA AND SPECIES 257 



(3) Hesperodrilus niger, BEDDABD. 

 H. niger, BEDDARD, loc. cit., p. 208. 



Definition. A stout species, black in colour. Dorsal setae begin upon first seligerous segment. 

 Hob. Port Stanley, Falkland Islands. 



This worm has very much the appearance of a Lumbriculus. It is much stouter 

 than either of those described. The black colour is due to pigment, which is chiefly 

 deposited in the peritoneum dorsally, extending into the musculature and also a little 

 way along the septa. The dorsal setae are rather slender. It is a curious point 

 about this worm that the spermiducal gland, though confined to the twelfth segment, 

 pushes the septum xi/xii before it so that it comes to lie as it were partly in 

 segment xi. This out-pushing of the septum in question begins when there are as 

 yet no signs whatever of the gland itself. 



(4) Hesperodrilus branchiatus, BEDDARD. 

 H. branchiatus, BEDDARD, loc. cit., p. 207. 



Definition. Last thirteen segments with a series of paired gills, attacked a little below the 

 lateral seta bundles. Spermathecae with a slight diverticulum at orifice. Hab. 

 Valdivia, Chili. 



This species is the only other Tubificid besides Branchiura, which has gills ; these 

 will be found more particularly described above (p. 84). The specimen which 

 I examined consisted of fifty-three segments, and was about three-quarters of an inch 

 long. I could find no proper sperm-sacs such as exist in the other species and in 

 other Tubificids. The sperm lay loose in the cavity of segments vii-xi. 



Genus HETEROCHAETA, CLAPAREDE. 



DEFINITION. Setae uncinate, except dorsal setae of "V-XIII, which are mainly 

 palmate. Dilated hearts in VIII. Spermiducal gland divisible into two 

 regions ; the glandular region (vesicular) not dilated ; penis chitinous ; prostates 

 present. 



This genus, originally described by CLAPAREDE (4), has been more fully dealt 

 with by BENHAM (9). It is mainly to be characterized by the peculiar palmate 

 setae which CLAPAREDE erroneously referred to as cup-shaped. They are in reality 



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