904 



REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



[26] 



and Chirodrillus ahyssorum, all of which are Americau species.* It is 

 even very doubtful if Chirodrillus ean be considered a Tuhificidce, it 

 having six fan-shaped fascicles of setse on each segment. 



The species from Eussia, described by Kessler, Nais papillosa, Nais 

 gigantea, Scenuris Jongicauda, may all be what we call good species, but 

 as yet we know too little of them to enable us to properly classify them. 

 Of a supposed identity of J^ais papulosa and Spirosperma I have spoken 

 under the heading of the latter species. 



Besides the above species, we know from Europe the following 10, viz : 

 Spirosperma, 1 species; Semitubifex, 1 species; Tubifex, 4 species; 

 Limnodrilus, 3 species ; and Psammoryctes, 1 species. 



The rest of the species are all from California. From the eastern 

 part of America I have not seen any species of Tubificidw, but have the 

 authority of several zoologists for their numerous occurrence. 



The following table will better show the distribution of the species : 



C— SPINES. 



The most prominent external characteristics of the species of this 

 family are derired from the spines. We can of them distinguish five dif- 

 ferent kinds or varieties, viz : 



1. Entire spines. 



2. Forked spines. 



3. Hair spines. 



4. Fan-shaped or comb-like spines. 



5. Pseudo-comb-like spines. 



* Ferrill, iu extract from report of S. F. Baird, Commissioner of Fisheries, Part II, 

 Rep. for 1872-73, pp. 697-699. 



