596 Transactions of the Society. 



19. Henlca triloba Friend. 



Length 10-12 mm. Segments about 45. Dorsal vessel, as in 

 K rnarina, arises abnormally in 12/13 where the intestine enlarges. 

 Body covered with glands. Coelomic corpuscles oval and spindle- 

 shaped, granular. The sets number 2-4 and the inner ones are 

 shortest." The front nephridia found in 8/9 and 9/10 (apparently 

 only 2 pairs) have postseptal much larger than anteseptal as usual. 

 The duct of the nephridia near the middle of the body is rather 

 long, and springs from the middle of the postseptal. One pair of 

 cesojihageal glands in 8th segment. Brain incised behind. Three 

 pairs of septals, trilobate. The intestine widens in 8/9 and again 

 in 12/13 where the dorsal vessel arises. The organs in the region 

 of the spermathecfe were too confused for definition, and it was 

 impossible to distinguish salivaries from spermathecse. 

 British Bcrord. — Hastings, December 21, 1911.* 

 This concludes the list of British species, so far as at present 

 known. A few others have been described, as H. gemmata and 

 H. ochracca by Eisen ; H. dorsalis, H. stolli, H. sulcata, and H.gul- 

 ieri by Bretscher ; H. lefrotji by Beddard, and H. scharffi by 

 Southern ; but they have not up to the present been met with in 

 Great Britain. Some of them are insufficiently described, and their 

 introduction is beyond the scope of our present study. It will 

 suffice, therefore, if in the following tabulation we include only the 

 species whose definitions have been supplied in the foregoing pages. 



IV.— Classification of Beitish Henleas. 



j Two pairs of spermathecge, in 3/4, 4/5 . . H. puteana (5) 



( One pair of spermatheca3 in 4/5 — 2 

 c I CEsophageal glands absent — 3 



I CEsophageal glands present — 12 

 ._, I Setse not exceeding 5 per bundle — 4 

 "■ t Setae exceeding 5 per ])undle — 7 



I Three pairs of septal glands— 5 



1 Four pairs of septal glands H. tenella {'.)) 



I Spermathecje with glands at 4/5 .... H. marina {lb) 



I Spermathecte without glands at 4/5 — 6 



I Salivary glands present H . cnriosa {12) 



\ Salivary glands absent H. lampas (7) 



„ I Salivary glands present — 8 



'■ 1 Salivary glands absent — 9 



^ I Small r length 5-8 mm., segments 25 . . H. rosai {6) 



I Larger : length lU-15 mm., segments 50 . H. dicTcsoni (3) 



* Since this paper was written^in May, one new species has been found by me^ 

 in Ireland, making the twentieth British species. 



4. 



6. 



