New British Enchytnrids. By Rev. H. Friend. 731 



breit, unverzweigt, vielfach verschlungen schlauchformig, durch 

 2 Segm. sicli erstreckend. Samentrichter klein, doppelt so lang 

 wie breit. Samentaschen mit dem Darm kommunizierend, 

 einfacb schlauchformig mit spindelformiger Ampulle, am distalen 

 Ende von einigen Driisen umscellt. — L. 3-4 mm., Segmz. 30. 

 Vielleicht mit E. argcnteus zu vereineri In nasser Erde. Schweiz 

 (Hittnau)." * 



This description is so clear and exact that a tyro in the study 

 of Enchytroeids would find it ample for the purposes of identifica- 

 tion. Michaelsen was familiar with Enchytrseus argcnteus, for it 

 was his own discovery. I myself described the worm in 1897 in 

 the Zoologist as E. 'parvulus. Michaelsen, however, had not seen 

 E. minimus Bret, when he wrote out the foregoing diagnosis, or he 

 would have recognized at once that they were distinct species. But 

 to distinguish them with absolute certainty one must have the living 

 forms under examination. 



I have made a full and careful study of both species, and as my 

 results confirm and extend Bretscher's description, I propose now to 

 transcribe my notes as they were made while the living creature 

 was under the Microscope. It is fortunate that I discovered the 

 species just at the right moment for observing the organs in their 

 mature condition. The study of immature forms may result in 

 difficulty, but when the creature is fully developed one has no 

 hesitation as to the interpretation. 



Enchytnvus minimus Bret, lives among decaying leaves and 

 vegetable matter. It is so small that one might easily pass it by, 

 but if damp material containing Enchytneids is kept for a time, so 

 that the surface becomes dry, the animals seek the moister parts 

 and gradually work downwards. Here they may be detected, 

 when present, by means of a pocket lens or the naked eye. The 

 present species is less than a quarter of an inch in length when 

 fully extended, and in alcohol is not more than one-eighth, or from 

 3-5 mm., while it is hardly 0*5 mm. in diameter. The number of 

 segments averages twenty-four, and they are of almost equal dimen- 

 sions throughout. The head is only slightly glandular, and the 

 head pore is situated between the prostomium and the peristomium, 

 being dorsal in position. 



The colour, as Bretscher remarks, is white, with a tendency to 



* Terreich, Oligochseta, pp. 92-3. Bretcher remarks (Rev. Suisse Zool., x. 

 (1902) p. 17 : — " Enchytrams argenteus Mich, gehort als neue Art ebenfalls der 

 Fauna der Schweiz an ; ich fand sie in den Erdproben von Zurich, Basel, Morges, 

 Trimmis, Riemenstalden. Michaelsen halt dafiir, dass mit dieser Spezies meine 

 E. minimus vielleicht vereinigt werden sollen. Nach dem ich nun unzweifelhafte 

 argenteus zu Gesicht bekommen habe, halte ich eine solche Vereinigung fiir un- 

 statthaft. Die Lymphkorper von minimus sind durchaus hell gefarbt ; die Driisen 

 an der Oeffnung der Samentaschen, die Verheiterungen des Bauchmerkes, der viel 

 schlankere Leib bilden fernere Unterscheidungsmale." See Southern Contribu- 

 tions towards a Monograph of the British and Irish Oligochseta, Proc. R. Irish 

 Acad., xxvii. sect. B, No. 8, p. 157. 



