20 PROCEEDINGS OF THE ACADEMY OF [Jan., 



2. H. rosai Bretscher. 



3. H. pratorum Br. 



4. H. sulcata Br. 



5. //. lefroyi Beddard. 



6. H. dorsalis Br. 



7. H. rhcetica Br. 



8. H. st oil i Br. 



None of these species have yet been recorded from North America. 

 They may be separated as follows: 



1. Salivary glands \ P**"* 2 ' 



• E \ absent 6. 



2. No sharp distinction between oesophagus and intestine H. lefroyi. 



Very sharp distinction between oesophagus and intestine 3. 



3. Nephridial duct rises at the front end of the postseptal....//. dicksoni. 

 Nephridial duct rises at the back end of the postseptal 4. 



4. Dorsal vessel rises in the 8th segment H. rosai. 



Dorsal vessel rises in the 7th segment 5. 



5. Nephridia with broad anteseptal H. pratorum. 



Nephridia with small anteseptal H. sulcata. 



6. Swelling of gut in the 8th segment 7. 



No swelling of gut in the 8th segment 8. 



7. Setae of anterior ventral bundles 4-6 H. dorsalis. 



Setae of anterior ventral bundles 6-8 H. rhcetica. 



8. Spermathecae uniform in width; dorsal vessel rising in the 



9th segment H. scharffi. 



Spermathecae differentiated into duct and ampulla; dorsal 



vessel rising in the 8th segment H. stolli. 



Members of this genus are characterized by the sudden change in 

 diameter of the gut, where the oesophagus passes into the middle 

 intestine, and by the frequent presence at this point of intestinal 

 outgrowths or pouches. In H. scharffi these pouches are absent 

 and the change in diameter is gradual, and is spread over half a seg- 

 ment. In this feature it bears some resemblance to the species 

 H. lefroyi, described by Beddard 4 from India. In the latter species 

 Beddard — working on preserved material — found that the oesophagus 

 passed without any abrupt change in dimensions into the middle 

 gut. The two species also resemble each other in being without 

 the intestinal pouches. The genus Henlea includes a somewhat 

 heterogenous assembly of species, and will probably be found to 

 contain several distinct generic types. However, the present 

 species may be placed provisionally in this genus. 



The type-specimen is preserved in the Irish National Museum, 

 Dublin. 



* Proc. Zool. Soc. London, 1905, II, pp. 61-64. 



