a remarkuhle Ephoic Oligoch(ete. 151 



willi thick muscular walls, containing spermatozoa in the 

 liinuMi; after running inwards till they nearly meet in the 

 nii(l(Jle line, the two organs turn backwards and outwards, 

 and end in blind expansions just in I'ront of the " calciterous 

 glands."_ 



Just in front of and behind the distal branch of the 

 spermathecae are two large crescentic organs of peculiar 

 histological structure, lying across the body-cavity from side 

 to side, dorsal to the oesophagus. Their nature is as yet 

 mjsteriuus, and it can oidy be said that they seem to receive 

 an abundant nerve-supply from the visceral system, repre- 

 sinft'd by a pair of ganglia lying just at the hinder and outer 

 an-Ks ot the pharynx. 



The nervous system, on the whole, is similar to that of any 

 annelid, the cerebral ganglia being situated in the first 

 segment, and connected by circum-pharyngeal connectives 

 with a double nerve-cord which lies along the ventral side 

 of the body, close to the body-wall, and is interrupted by a 

 pair of ganglia in every segment. 



Tiie blood-vascular system has not yet been worked out, 

 but some portions of branches of what would seem to be a 

 subneural vessel have been detected near the head end of 

 the worm. 



The following is a brief generic diagnosis : — 

 ASPIDODRILUS, gen. nov. 



Small Oligochaita, having the posterior half of the body 

 flattened and expanded into an oval disc bearing numerous 

 transverse rows of cha^tai ventrally. Anterior segments each 

 bearing two pairs of short, straight chajtaj. ('litelluni occu|)ies 

 segment xi. ; on the ventral side of that segment there is a 

 muscular sucker, at tiie edges of which are the openings of a 

 pair of sperm-ducts. 



Ovaries, four pairs, situated in ix.-x., lying free in coclom ; 

 ova large, with much yolk. 



JSpermathecce open in iii. Sperm-sacs in viii.-x., with 

 large sperm-funnels in x. ; sperm-ducts long and coiled. 



Species, A. kelsalli, sp. n. 



With the characters of the genus. 



Length 5 mm. 



Livin^f attached to the exterior of a larjie eartliworm. 



Uab. Sierra Leone, West Africa. 



Type specimens iu the British Muieum (Natural History). 



