380 OLIGOCH AETA 



contractile and blind appendages, which were at first mistaken for 

 caeca of the intestine itself. There are two genera of this family 

 in North America, which are not very different anatomically from 

 their European representatives. The genera described by Eisen 

 are Sutroa l and Edipidrilus? The latter lives in cold torrents at 

 a great height in the mountains of the Sierra Nevada of California. 

 FAM. 8. Moniligastridae. This family, terrestrial in habit, 

 is probably Oriental in range ; but I have described a single 

 species from the Bahamas which may possibly be referable to 

 the category of accidentally introduced specimens. Our know- 

 ledge of this family is conveniently summed up in Professor 

 Bourne's paper 3 upon the genus Monilig aster. There are some 

 eighteen species, which range in size from an inch or so in 

 length (M. bahamensis} to about two feet ; this last measurement 

 is that of the huge M. grandis, of which, together with many others, 

 Professor Bourne gives coloured drawings. There is a second 

 genus, Desmogaster, which is mainly characterised by the doubling 

 of the reproductive organs. This was described by Kosa from 

 Burrnah. The family is noteworthy on account of the fact that 

 every species belonging to it has at least four distinct gizzards, 

 sometimes more ; but as this multiplication of the gizzards has 

 been also found in Heliodrilus among the Eudrilidae, and indeed 

 elsewhere, it is insufficient to define the family. More character- 

 istic is the fact that the sperm-ducts open on to the next segment 

 to, or even the same segment as, that which contains their funnels ; 

 consequently the apertures of the oviducts are behind instead of in 

 front of them. These pores are also situated in a very anterior 

 position, the male pores being upon the tenth segment or between 

 the tenth and eleventh, and the oviducal pores upon the follow- 

 ing one. In these features the family presents resemblance to 

 the aquatic Oligochaeta, from which, however, its stoutly-built 

 gizzards, and vascular nephridia differentiate it. 



II. Megadrili. 

 FAM. 9. Perichaetidae* The Perichaetidae comprise a larger 



1 "Anatomical Notes on Sutroa," Zoe. ii. 1892, p. 321. 



2 " Pacific Coast Oligochaeta," Mem. California Acad. Set. vol. ii. 



3 Quart. J. Micr. Sci. xxxvi. 1894, p. 307. 



4 See Spencer, Proc. Roy. Soc. Viet. v. 1893, and Fletcher, P. Linn. Soc. N.S. W. 

 1886-1888, for Australian forms ; Rosa, Ann. Mus. civ. Genova, vi. 1886, x. 1890, 

 and xii. 1892, for Oriental species, etc. 



