332 OLIGOCHAETA 



but not described), have a very short anteseptal part; the duct arises some little 

 way behind the septum. 



(4) Marionia crassa (CLAPAKEDE). 



Pachydrilus crassus, CLAPAREDE, Me"m. Soc. Phys. Gen., 1862, p. 79. 

 M. crassa, MICHAELSEN, Abh. Nat. Ver. Hamb., 1 889, p. 29. 



Definition. Length, 15 mm.; number of segments, 48; setae, 2-5 per bundle. Spermathecae 

 furnished at base with minute glands. Lymph corpuscles of two different kinds. Hal). 

 Island of Skye. 



It seems to me to be a little doubtful whether this species is really referable to 

 the genus Marionia or to Pachydrilus. The sharp demarcation of two kinds of lymph 

 corpuscles is not met with elsewhere in the genus, and is used by MICHAELSEN to 

 distinguish the species from other Marionia. Some of the cells are roundish with 

 numerous granules, the others have the form more usual in the genus and are fusiform 

 with no granules. Another point in which the species differs from other members 

 of this genus or the last is in the form of the ' testes.' CLAPAREDE describes them 

 as extending from the eighth (ninth) to the eleventh (twelfth) segment, an extent 

 which is suggestive rather of sperm-sacs than testes. The fact that the organs in 

 question are unpaired l is in favour of this suggestion. I do not pretend to speak 

 decisively upon the matter, which requires looking into. 



(5) Marionia georgiana, MICHAELSEN. 



Pachydrilus georgianus, MICHAELSEN, JB. Hamb. Wiss. Anst., 1888, p. 65. 

 M. georgiana, MICHAELSEN, Abh. Nat. Ver. Hamb., 1889, p. 29. 



Definition. Length, 8 mm. ; setae, 5-7 per bundle. Spermathecae with feio glands at pore. 

 Dorsal vessel springs from a cup-like depression upon intestine. Ilab. South Georgia. 



The last character in the definition distinguishes the species. The duct of the 

 spermatheca is about half the length of the pouch. Septal glands are developed in 

 segments iv, v, vi. The dorsal vessel originates at end of thirteenth segment. 



1 < i u'Ai;i m uses the singular in writing of them. But so does he in the species M.fusca, so that this is 

 perhaps not quite enough reason for inferring that the organs are unpaired. D'UDEKEM, however, describes 

 as 'unique,' and figures as single, the ovary of Fridericia galba. 



