I 



Earthworms from Celebes. 435 



pair just in front of the septum vii./viii. Apparently there 

 is no vessel in segment viii., nor are there any in segments 

 xiv. and xv. ; but posteriorly in and after segment xvi. the 

 dorsal vessel gives off a pair of nearly vertical vessels to 

 body-wall as well as two pairs to gut. 



The dorsal vessel is provided with a pair of " glycogenic 

 glands" on each of the posterior segments. 



With regard to the generative organs, there are two pairs 

 of sperm-sacs in segments xi. and xii., of relatively small size 

 and of smooth surface. How these are related to " sperm- 

 bladders " (" Samenblasen ") I cannot say, as I did not wish 

 to injure the specimen too much, and I do not consider this 

 point of great importance. 



Grape-like ovisacs of large size lie in segment xiv. con- 

 tinuous with large sac-like oviducts. 



The spermathecce lie in segments viii. and ix., tliose of the 

 eighth segment being about one fourth the size of the other 

 pair. Each spermatheca consists of a somewhat pyriform sac 

 with a long duct, into which opens an undulating diverticulum 

 terminating in a slight dilatation (fig. 2 J). 



This verbal description so closely resembles that given for 

 P. jampeana^ that one might easily imagine that the two 

 species had the same shaped spermathecas ; and it is a most 

 iinportant point, it seems to me, to illustrate these diagnostic 

 organs in the Perichcetce. A careful figure, to measurement 

 for preference, will do more than many words of description 

 to give an idea of the characters on which the species are 

 founded. Many species of this difficult and extensive genus 

 are known only from verbal descriptions, some of the terms 

 employed being extremely " loose," and it is a matter of 

 great difficulty to pick out the diagnostic characters of a 

 species from a mere verbal description. Nevertheless, it must 

 be borne in mind that the size and even shape of the main sac 

 is liable to variation according to its state of repletion. 



The same remarks apply to descriptions of the spermiducal 

 gland : such terms as " compact," " loosish " in texture, 

 unless accompanied by figures, are absolutely insufficient 

 whereby to form a mental picture of the organ. 



In the present species the spermiducal gland is entirely 

 confined to the eighteenth segment and has a very charac- 

 teristic form. It is arranged in the form of a horseshoe, the 

 convexity outwards, embracing by its two limbs the thick 

 straight duct. This duct passes at right angles to the long 

 axis of the worm, then, after widening slightly, dips suddenly 

 downwards, and runs under its former course, to gain the body- 

 wall. There is no " muscular bulb." 



