318 
ENCHYTRAEIDS OF THE NORTH OF ENGLAND. 
Rev. HILDERIC FRIEND, F.I.S., F.R.M.S., 
Swadlincote. 
By means of some new methods which I have been able to 
adopt with the aid of a Government Grant, I have recently 
worked out a number of small species of Enchytreids which 
had hitherto largely escaped observation. It may be well in 
the present paper to take a somewhat careful survey of another 
genus belonging to this family, and I therefore select Henlea. 
This genus was created by Michaelsen in 1889, the name being 
derived from that of Henle, an early authority in Zoology. 
It includes certain species which had previously been entered 
under such generic titles as Enchytreeus, Archienchytreus, and 
Neoenchytreus, together with certain more recent discoveries. 
Beddard, in his valuable ‘ Monograph of the Order Oligochaeta,’ 
1895, gives four species as well-known, and alludes to some 
others as doubtful, but, though they were all known to be 
European, there is not a hint that any species of Henlea was 
to be regarded as British. I was the first to draw attention to 
the fact that the genus was represented in these Islands, as a 
reference to this Journal and the Essex Naturalist for 1896 will 
shew. 
In 1900, when “ Das Tierreich’ was published, Michaelsen 
enumerated five species, and gave four others as uncertain. 
The uncertainty was generic, not specific. It is true the four 
which he withholds from full recognition were not as carefully 
described as they would be to-day ; but Eisen, who published 
the descriptions in 1878, is a first-rate authority, and two of 
his species were admitted. I believe that in time it will be 
possible to fit all his species into their proper places. Since 
Ig00 new species have been added by Bretscher, Beddard, 
Southern, and myself, so that the genus is now assuming con- 
siderable proportions. The species, which are fully determined, 
will be set forth in the order in which they were discovered by 
myself in this country. 
It may be helpful to students, if, before cataloguing the 
species, I state the distinguishing marks of a Henlea. Beddard 
has drawn attention to the fact that we have, perhaps, a some- 
what heterogeneous assemblage of species here, but that can 
be corrected as our knowledge grows. First there are certain 
negative characters, such as the absence of dorsal pores—always 
present in Lridericia—the absence of diverticula from the 
spermathece, and the absence of a dorsal vessel behind the 
girdle. Salivary glands or peptonephridia may or may not be 
present. The oesophagus is sharply marked off from the 
intestine about the eighth segment, in which, or in one of the 
adjoining segments, the dorsal vessel arises. The sete differ in 
Naturalist, 
