NEW MEGASCOLEX. 
97 
At the anterior part of the body the setae are placed in regular 
longitudinal rows, forming four rather wide pairs in each segment, 
those of the dorsal pairs ( cd ) being somewhat, but only a little, 
further apart from one another than those of the ventral pairs ( ab ), 
and the latter somewhat farther apart from one another than the 
neighbouring setae of both pairs (b and c). The median ventral 
interspace is about twice as wide as the distance between the setae 
of the ventral pair. The median dorsal interspace is about five times 
as wide as the distance between the setae of the dorsal pair. The 
different interspaces between the setae of the eighth segment may be 
indicated by the following proportional measurement:— aa : ab : be : 
cd : dd = 24 : 12 : 14 : 13 : 64. The setae of the a series are regularly 
placed in two straight rows throughout the whole body. In most 
of the specimens the other setae also form regular longitudinal rows 
throughout the middle and posterior parts of the body, after having 
increased to 12 per segment. 
The somewhat varying arrangement of them majf be indicated 
by the following proportional measurements taken at the twelfth 
segment from the hinder end of the body :— aa : ab : be : cd : de : ef : 
ft = 24 : 12 : 12 : 11 : 12 : 11 : 45 ; and again at the third segment 
from the hinder end :— aa : ab : be : cd : de : ef : ff = 24 : 12: 12 : 
10 : 13 : 13 : 26. In some of the specimens examined the arrange¬ 
ment of the setae b, c, d , e, and / becomes irregular in the hinder 
half of the body, the irregularity beginning with the dorsal rows 
e and / about the middle of the body, whilst the ventral and 
lateral rows b, c, and d are still regular ; these become irregular 
further back. Once only I found this irregular arrangement 
of the setae associated with an increase of their number as 
mentioned above, eight on one side and six on the other in one 
segment. 
The dorsal pores are very conspicuous ; the first pore lies in the 
intersegmental furrow IX./X. 
The clitellum is distinguished by its darker colour. It is ring- 
shaped, and occupies the four segments XIV.-XVII. The fore 
margin of the fourteenth and the hinder margin of the seventeenth 
segment are often less modified than the intervening tract. 
The male pores are placed in segment XVIII. in the line of setae 
of the series^, if not a little lateral of this row, on each side. They 
are borne at the summits of a pair of penial protuberances, which 
appear to be non-re tractile. These protuberances arise by a broad 
basis from the posterior half of the eighteenth segment, and have a 
rather sharply pointed, nearly equilateral triangular shape, flattened 
antero-posteriorly, and bent over forwards. Sometimes the pro¬ 
tuberances are connected with one another by a median transverse 
ridge, which is also inclined forwards, and partly covers a 
transverse depression occupying the fore part of the segment medio- 
ventrally. 
