KEPOKT OX THK OLKiOCILETA — HEXHAM. 'IQO 



The capillifunns of the anterior segments are nuicli longer tlian 

 those at the hinder end, and there is a gradual diminution back- 

 wards. 



One of these cluetie from segment vii. measures 5 mm., while 

 one from near the hinder end measures only l'S7 nun. totai 

 length. 



The crochets of the dorsal bundles have the two teeth of equal 

 size and form, diverging somewhat from each other, but the 

 "lower" tooth is not curved away for the "upper." 



The number of ch;etie in the dorsal bundles of the anterior 

 segments is shown in the following table : — 



Tile ventral ch;et;e are crochets throughout the body and 

 usually are three or four per bundle. Tliose of the anterior 

 segments are larger in all dimensions than those of the rest of the 

 body. 



The two teeth are nearly of etjual length, but the distal (oi- 

 upper) tooth is the more slender, the proximal (or lower) tooth 

 being curved away from it in the usual typical manner (PI. xlvi., 

 fig. 3). In the anterior segments the two teeth are much more 

 different in form, the proximal being stouter and the distal still 

 more slender, so that it appears to be rather larger. 



As is generally the case in the family Tubificidye, there are no 

 chfftje. either dorsal or ventral, on segment xi. of the mature 

 worm, though they are present in the immature individuals ; in 

 one indiviflual, in which the genital organs were not yet fulh' 

 develoi)ed, there is still one capilliform clueta remaining in the 

 dorsal bundle of this segment, indicating, of course, that the 

 bristles drop out as the worm attains its full sexual de\ elopment. 



In segment x. of the immature worm, the ventral chieta; have 

 the normal shape and arrangement; but these also drop out as 

 maturity is approached, and each bundle becomes represented by 

 a single " copulatoiy clueta " of special form and surrounded l>y 

 a spherical gland (PI. xlvi., fig. 6). 



The copulatory clueta is a delicate, slightly curxed icul, with a 

 simple blunt pohit, not recurved. It measures 0-1U5 mm. and is 

 much slenderer than a ventral clueta, and shorter (PI. xlvi., 

 fig. 4). The copulatory cha^ta, indeed, is .so delicate, that 



