Benham. — On Eartlnvorms. 141 



segments 11, 20, and 21, or 11, 21, and 22 ; in a few cases an 

 additional pair may exist.* 



I was unable to find any dorsal pores, even when the 

 body-wall was mounted. 



Internal Anatomy. 

 The dorsal vessel is single ; the last heart is very large, 

 lying in 12th segment, those in 10 and 11 being smaller. The 

 worm is meganephric. 



Alimentary Tract.— The gizzard, rather long, occupies the 

 6th segment ; the oesophagus, with vascular walls, bears a 

 single pair of "oesophageal glands" in the 13th segment. 

 Intestine commences in the 18th, and is without a typhlo- 

 sole. 



Reproductive Organs. — The two pairs of testes lie in the 

 normal segments. There are two pairs of lobulated sperm- 

 sacs in segments 11 and 12 attached to the anterior wall, 

 while the two segments 10 and 11 are filled with loose sper- 

 matozoa. The sperm-duct is slightly muscular at its hinder 

 end as it enters the body-wall, passes behind the duct of the 

 gland, and opens through the porophore by an independent 

 aperture. The spermiducal gland is relatively large, extend- 

 ing backwards as far as the 25th segment, accompanied by 

 the long sac with penial chastae. The gland is somewhat 

 tongue-shaped, and slightly curled at the posterior end ; its 

 muscular duct is short, limited to the 17th segment, and 

 opens to the exterior in front of the sperm-duct and inde- 

 pendently of it. The sac of penial chaetse opens by the same 

 pore, though practically it is independent of the duct. The 

 two pairs of spermathecaa lie in segments 8 and 9 respec- 

 tively ; each is a pyriform sac, with a thick muscular duct of 

 its own length, with a diameter rather less than half that of 

 the sac. There is a single tubular diverticulum opening near 

 the end of the duct ; it is relatively wide, slightly undulating, 

 and not distended distally. Its diameter is greater than the 

 duct, and its length about twice that of the sac and duct 

 together. 



Affinities, dc. — The present addition to our fauna makes 

 the fourth species of Microscolex known to inhabit the Islands 

 of New Zealand, for Mr. F. E. Beddard has already de- 

 scribed three species. Though the descriptions are somewhat 



* The facts of the variation may be summarised thus : In six speci- 

 mens suckers are on segments 11, 20, and 21 ; in six, en 11, 21, and 22 — 

 in four of these additional suckers, small or unpaired, are present on 23 ; 

 in one case, on 11, 19, 20, and 21 ; in one case, on 10, 11, and 21; in 

 one case, on 11, 22, and unpaired on 23 ; and in one case, on 11 and 20. 

 The 17ch specimen is immature. There is thus a tendency to add 

 suckers posteriorly. 



