642 OLIGOCHAETA 



This species has been fully described and figured by Benham. The principal 

 diiFerences which distinguish it from other species are the absence of any specially 

 modified setae, and the presence of seven instead of three or six pairs of calciferous 

 glands. It is also remarkable for the fact that there are no* setae until the third 

 segment of the body. It may be, as I have already suggested, that R. gulielvii 

 agrees with the present species in this peculiarity, which may even prove to 

 characterize the genus. The typhlosole is curious : it is well developed, and instead 

 of passing in a straight line along the dorsal wall of the intestine, its line of origin 

 takes a spiral course round the wall of the gut. 



The dorsal vessel communicates with the ventral by means of three peri- oesophageal 

 trunks in segments viii, ix, x; there are two intestinal hearts in the two following 

 segments. The dorsal vessel itself appears to end abruptly behind the gizzard ; but 

 this unusual divergence from the normal requires confirmation. It is figured by 

 Benham as ending at the first pair of peri-oesophageal trunks. 



(7) Rhinodrilus callichaetus (Michaelsen). 

 Anteus callichaetus, Michaelsen, Arch. f. Nat., 1892, p. 320. 



Definition. LenfftA, 10^ mm.; Ireadth, ^mm..; number of segments, \o^. Setae ornamented ; 

 ventral commence in segment V, dorsal in segment VIII. Nephridiopores begin in 

 segment III, placed in front of lateral setae. Clitellum, XV-XXIV. Male pores on 

 XIX-XX [?). Two pairs of calciferous glands. In segments XVIII-XXII pairs rf 

 glands, between which are sacs of long ornamented setae. Spermathecae in VII, VIII, 

 in the neighbourhood of which are copulatory setae like the posterior setae. Hab. — Caracas. 

 This species is said to show very active movements when alive like a Perichaeta, 



and to be dark-violet coloured. The gizzard is in ix, x. Septa all very slender, 



those of anterior segments seem to be reduced. 



(8) Rhinodrilus proboscideus, Sohneidee. 



B. proboscideus, Schneider, SB. Dorpat. Nat. Ges. Jhrg., x, 1893, p. 44. 



Definition. Length, 190 mm.; number of segments, 130. Setae smooth, excepting pairs of 

 ventral side of XIX-XXI. Clitellum, XV-XXIV. Sperm-duct pores on XX; oviducal 

 pores on XVII/XVIII. Unpaired ovary in XVII. Spermathecae two pairs in VII, VIII. 

 Hab. — Trinidad. 



This very remarkable species is referred to Rhinodrilus with some little doubt ; 

 the principal reason for so referring it is the long retractile prostomium, which, as 



