.4 KEY TO BRITISH HENLEAS. 



89 



Key to the Genera. 

 Two Groups are recognized, viz. : — 



I. Species lacking oesophageal glands . Henleanella. 

 II. Species possessing oesophageal glands Henlea. 



The following belong to Group I. 

 Henleanella : (Esophageal glands absent. 



1. Two pairs of septal glands 



2. Four pairs of septal glands 



3. Three pairs of septal glands — 



i. Setae not exceeding five per set — 

 a. Dorsal vessel clitellian — 

 f Salivary glands absent 

 ft Salivary glands present . 

 ftt Abnormally placed glands 

 f3. Dorsal vessel anteclitellian — 



t Sperm-funnel spindle-shaped . 

 ft Sperm-funnel pear-shaped 

 ii. Setae exceeding five per set — 

 a. Two pairs of spermathecae 

 /3. One pair of spermathecae — 



t Duct of nephridia from posterior — 

 :;: Salivaries present 

 ** Salivaries absent . 

 ft Duct of nephridia from anterior — 

 * Salivaries present — 



(1) Slender or forked 



(2) Sac-like in 4-5 . 



(3) Unusual type of glands 



(4) Of normal form . 

 *-* Salivaries absent — 



(1) 

 (2) 

 (3) 



(4) 



Dorsal vessel arises in 7-8 . 

 Dorsal vessel arises in 8-9 . 

 Dorsal vessel arises in 9 — 



a. Length 2-3 mm. 



(3. Length 7-8 mm. 

 Dorsal vessel arises in 10-11 



H. mariona. 

 H. trisetosa. 



H. marina. 

 H. curiosa. 

 H. alba. 



H. tenella. 

 H. lampas. 



H. puteana. 



H. rosai. 

 H. parva. 



H. multispinosa. 

 H. minuta. 

 H. inusitata. 

 H. clicksoni. 



H. glandulosa. 

 H. arenicola. 



H. perpusilla. 

 H. rhcetica. 

 H. minima. 



The following belong to Group II. 

 Henlea : Oesophageal glands present. 



1. Two pairs of oesophageal glands 



2. One pair of oesophageal glands in segment 7- 



Three pairs of septal glands — 

 a. Dorsal vessel arises in 7-8 — 

 * Salivary glands present 

 ** Salivary glands absent 

 ft. Dorsal vessel arises in 8 . 



H. ventriculosa. 



H. attenuata. 

 H. heterotropa. 

 H. nasuta. 



