350 OLIGOCHAETA 



is unique in the whole family; this species also has straight setae like those of the 

 genus Enchytraeus, while in H. dicksonii the setae are ./-shaped, as in the genus 

 Pachydrilus, &c. The following species, at least, appear to be well characterized : — 



(i) Henlea ventrieulosa. 



(a) Henlea leptodera. 



(3) Henlea puteana. 

 Besides these three, Michaelsen has assigned three others to the genus: viz. 

 H. socialis, H. iiasuta, and ff. dicksonii. The latter has heen investigated by Eisen 

 and by MiCHAELSEN ; more recently, Ude has added something to our knowledge 

 of this species, which may be now removed from the doubtful position it held at 

 the time that Michaelsen wrote. 



'Enchytraeus socialis' of Leidy (6) is queried as a member of the genus Enchytraeus by Vaillant 

 (6, p. 291) ; but it must, of course, be remembered that Enchytraeus, with that naturalist, is used in 

 a very wide sense. 



The only salient point in the description of the species is that it possesses a dilatation upon the 

 oesophagus in the eighth segment, a fact which led Michaelsen to place it in the present genus. 

 No more than this can be said. 



The well-known species can be distinguished by the following table : — 



I. Two pairs of spermathecae H. puteana. 



11. One pair of spermathecae. 



(i) No oesophageal glands H. dicksonii. 



(3) Two oesophageal glands H. leptodera. 



(3) Four oesophageal glands ... . . H. ventrieulosa. 



• 



(i) Henlea ventrieulosa (d'Udekem). 

 Enchytraeus ventriculosus, d'Udekem, Bull. Ac. Roy. Belg., 1855, xxii. pt. ii. 



P- 547- 

 E. latus, Letdig, Vom Bau des thierischen Korpers, 1864 (Fide Michaelsen). 

 E. (Arehienchytraeus, Eisen) ventriculosus, MichAELSEN, Ench. Mob., 1886, p. 46. 

 E. (Archiencliytraeus) albidus, Vaillant, Annelds, p. 281 (in part.). 

 Arehienchytraeus ventriculosus, KosA, Boll. Mus. Zool. Torino, 1887, No. 39. 

 Henlea ventrieulosa, Michaelsen, Abh. Nat. Ver. Hamb., 1889, p. 31. 

 Definition. Lengih, 15-30 mm.; number of segments, 60; setae straight or slightly bent to 

 right or left, 4-9. Four oesophageal glands. Eab. — Germany; JDenmarh ; Bohemia; 

 Italy ; Belgium; New Zealand; Asia. Terrestrial. 



The first describer of this species, d'Udekem, omitted a large number of details in both his 

 description and his figures; some of these omissions, however, are probably due to the real absence 



