Ih4 BULLETIN OF THE BUKEAU OF FISHERIES. 



lu.iterial was sent to me for deteniiination. Most of the work in l.SD.S was done in 

 the immediate vicinity of New Baltimore, at the northern extremity of Lake St. 

 Clair, and so far as relates to the group of animals under consideration by Prof. 

 II. B. Ward, who furnishes some careful notes and drawings of several species. A 

 preliminary report on the field operations has been published as Bulletin Mo. i of 

 the Michigan fish commission (Lansing, 1894), in which will be found some account 

 of the physical and biological conditions of the region. The Oligochsta were origi- 

 nally sent to Dr. Eisen, who made a preliminary examination and brief report, 

 but has been prevented from completing his studies. Dr. Eisen's list, published 

 in the above-mentioned bulletin, is as follows, the name included in parenthesis fol- 

 lowing each of Eisen's determinations being, so far as can be determined, the corre- 

 sponding name in the present report: Genus related to Thamnodrihis {Sparganophilus 

 eixeni); newgenusof ljn\\\hvic\x\\Ai% [Tlunodrilns inconMnns)', twospeciesof Stylaria 

 {S. lacusfris and S. fosnularis); BohemUla sp. (not found); Pristina {P. Jeidyi); 

 Xdidiiiiii (not found), and Chxtoyaster {€'. diaplmnus and C. llmsei). The collections 

 in Lake Erie were made chiefly in the vicinity of the Bass Lslands, Sanduskj', and 

 other points at the western end of the lake, though a few Oligochaeta were taken at 

 Erie, Fa., and at points on the Canadian shore. 



As most of the 15 species included in the two collections are well known either 

 in this country or Europe, no descriptions of them are given in this paper, but after 

 the name of each there is inserted a reference to one of the best easily accessible 

 published descriptions, in nearly ever}' case well illustrated. A key has been added, 

 however, for the discrimination of the species, and the characters given are suflicient 

 in most cases to separate them with considerable certainty from related species 

 inhabiting the same waters. A full list of the localities at which each species was 

 taken is given, the parenthesized number referring in each case to the station, and 

 the data that follow being transcripts of the labels. Of the 15 species enumerated, 

 1(1 belong to the strictly aquatic family NaididiB and probably i-epresent the majority 

 of those likely to occur in this fauna. Several additional species of the ^Eoloso- 

 matidse and Lumbriculidfe and many of the Tubificidre are likel}' to be met with in 

 the watei's of the Great Lakes, while many Lumbricidse and other earthworms have 

 already been recorded from the bordering states. 



Kcfi to species of bligochscta reported npoii. 



n. Size small; reproduction chiefly by means of serial asexual buds; sexually mature individuals 



rarely found; digestive tract simple; always strictly aquatic. 



b. Central nervous system imperfectly developed, intimately connected with epidermis throughout; 



internal metamerism incomplete owing to the absence of some or all of the dissepiments. 



(^Eolosomatidse. ) 



r. In addition to capillary setse the posterior bundles at least contain alternating shorter, straight, 



curved, or bifid sette; prostomium broader than peristomium; integumental oil drops usually 



with a yellow or green tint Jikilosoma tenel/raruni (p. 166). 



bij. Central nervous system complete, the brain, at least, quite distinct from the epidermis; dissepi- 

 ments completely developed; forked setse exclusively present in ventral bundles. (Naididse. ) 

 (!. Prostomium distinct and more or less prominently developed; somite III not enlarged and 

 the pharynx small and much shorter than tlie cesophagus; number of somites not greatly 

 reduced; ventral sette normally present on all somites behind the peristomium. 

 e. Prostomium produced into a papilliform or tentacular process. 



