GO-t Dr. F. E. Bcddara on 



not at variance with tlic possibility tliat tliey arc to l)e 

 looked upon as evidence of the originally paired condition 

 of the spermathecal sac, which is hekl to be the primitive 

 state of affairs in the Endrilidae as in other families. In 

 this case Notykus wonld bear the same relationship amongf 

 the Pareudriliacea to the forms with paired (e. g., Pnren- 

 drilus) and unpaired (e.g., Eudriloides) orifices, as does the 

 genus GarduUaria among the Eudrilacea*, to corresponding 

 forms in tliat group. 



On this hypothesis, the single median pore of the sper- 

 mathecal sac would have to be a new formation, the original 

 pores with their muscular ducts being converted to another 

 function. That there is no necessary difficulty in this is 

 shown by the case of Pohjtoreutus multiporus f, in whieli 

 species that sac does form supplementary external pores. 



In the two fully mature individuals the conditions are a 

 little different. When examined from above (specimen A), 

 the muscular part of the spermathecal sac is seen to be 

 mostly covered over by a large muscular flap, one on each 

 side; this presents the appearance of a thickened septum, 

 and, as I point out later, may indeed be its derivative. A 

 closer examination of this sheet of muscle shows that it is 

 in reality a sac — empty, so that its two walls, dorsal and 

 ventral, are in contact, thus giving to it the appearance of 

 an empty coal-sack lying across the rounded mass, which it 

 partly conceals. The two sacs seem to be continued an- 

 teriorly into a thin membrane covering the anterior portion 

 of the spermathecal sac. When the two walls were divari- 

 cated by pushing a mounted needle between the two walls, 

 the sac was seen to be prolonged downwards towards the 

 ventral median line of the body. To the side of and behind 

 these sacs lay on each side of the body the receptaculum 

 ovornm. The position of this latter thus differs in the more 

 mature individual. This may be produced, of course, by 

 the growth of the flattened muscular sacs intervening. 



In the bisected individual (C) the conditions can be 

 further examined, and their relationships to other structures 

 seen from the lateral point of view. Among other things, 

 the exact number of segments occupied by the spermathec;d 

 sac can be detected. The anterior muscular part of this 

 organ reaches from the I3th to the end of the 14th segment. 



* Micbaelseii, "Die 01ij>och8eten Nordost-Afrikas," Zool. Jahrb. xviii. 

 (1903), p. 498, Taf. xxv. fig. 23 ; see also id., " Die Olifrochajten Deutscli- 

 Ostafrikas," Zeitsch. wiss. Zool. Ixxxii. (1905), p. .301,' fi"-. 



t Smith and Green, "Descriptions of new African Earthworms &c.," 

 Proc. U.S. Nat. Mus. Iv. (1919), p. 163. 



