MEGADRILI 387 



in any undoubted Lumbricid. The peculiar elongated cocoon, 

 which much resembles that of Sparganophihis, is another char- 

 acter which favours its Geoscolecine affinities. Dr. Michaelsen has 

 proposed to unite Criodrilus and Alma into a family intermediate 

 between the Geoscolicidae and the Lumbricidae. 



Perhaps the most remarkable genus in the whole family is 

 Alma. One species lives in the Nile mud ; another is the 

 " Yoruba worm " of West Africa, whose habits have been de- 

 scribed by Mr. Millson. The most marked character of this genus, 

 apart from the branchiae (see p. 352) which apparently may be 



FIG. 198. Alma millsoni F. E. B. x 1. 



present or absent according to the species, is in the two enormous 

 processes of the body-wall, which are illustrated in Fig. 198. 

 These contain the sperin-ducts, which, however, open some way 

 in front of the free end ; they are provided on the ventral surface 

 with a series of sucker-like structures and with peculiar chaetae. 

 Another interesting genus is Pontoscolex, which was originally 

 described from the sea-shore of Jamaica by Schmarda ; there are 

 only two species which are certainly characterised, though a variety 

 from the Hawaiaii Islands may be a " good " species. It possesses 

 the remarkable peculiarity that the chaetae at the end of the 

 body are disposed in a perfectly irregular fashion, which earned 

 for it the name of brush-tail at the hands of its discoverer, Fritz 



