98 EISEN 



Genus Henlea Michaelsen. 



Definition. — Setae variable (like Fridericia or Lumbricillus) . 

 Head-pore small, situated between prostomium and somite I. No 

 dorsal pores. Esophagus narrow and suddenly merges into the 

 intestine. Intestinal diverticles generally present. Dorsal vessel rises 

 anterior to the clitellum. Blood colorless. Lymphocytes large, disc 

 shaped. Brain posteriorly emarginated. Nephridia generally with 

 large anteseptal. Spermatheca generally without diverticles. Sperm- 

 ducts comparatively narrow and long. Penial bulb without interior 

 muscular strands (^Lui7ibricillus bulb). Chylus cells in the intestine 

 in the vicinity of clitellum. 



Affinities. — The genus Henlea as now established is undoubtedly 

 nearest related to Bryodrilus. Both genera agree in the most remark- 

 able variation in the various organs. The only real distinction be- 

 tween the two genera lies in the origin of the dorsal vessel. In both 

 genera we find a variation in the form and comparative length of the 

 setae. These may be either sigmoid (^Lti?nbricillus-?>\\a.-ped)^ straight 

 (^Enckyt7'ceus-s\\a^edi).i or straight and of uneven size (^Fridericia' 

 shaped) . The nephridia of the new species are characterized by large 

 anteseptal, probably characteristic of the genus. Salivary glands may 

 be absent, rudimentary, or much enlarged. Even the structure of 

 the penial bulb seems similar in the two genera. The structure is 

 characterized by its two sets of glands, some of which open into the 

 sperm-ducts, while others open into small pore-like depressions on 

 the surface around the base of the penial pore. The presence of intes- 

 tinal pouches seems to be the rule, there being only a single exception. 

 I have followed Michaelsen in referring H. dicksoni to this genus, 

 but I am doubtful as to its correctness. The absence of intestinal 

 pouches, and a small anteseptal distinguishes that species from all 

 others in this genus. These two characteristics are of so great impor- 

 tance that we may well doubt the systematic place of that species. 



SYNOPSIS OF THE SPECIES OF HEXLEA. 



I. Two PAIRS OF SPERMATHEC^, IN IV AND V. 



Spermatheca without distinctly differentiated ampulla and without diverticles. 

 Setae in ventral fascicles 8 to 10, in lateral fascicles 5 to 7, arranged in a fan- 

 shaped manner i. H. puteana Vejd. 



II. One pair of spermatheca only, in V. 

 I. Spermathecse without diverticles. 



Spermatheca slender, with the ampulla hardly wider than the duct. The 

 inner setse in each fascicle smaller. Brain posteriorly concave. Two large 

 intestinal pouches in VIII. Anteseptal comparatively small. Large pep- 

 tonephridia 2. H. calif ortiica sp. nov. 



