SOME ANNELIDS OF THE THAMES VALLEY. 



103 



Bretscher gives 20 to 1 as the proportion.''' (This is not exactly true, for 

 Bretscher says " Penisscheide .... ilher 20-ma] lauger als breit""). "The 

 sheath has a broad and shallow funnel-like expansion at the distal end. 

 The anterior nephridia are enveloped in bladder-like cells. The length is 

 20-25 mm., and there are 4-7 setse in the anterior bundles." 



My own notes are as follows: — " L. longxis, Bret. In mud from Tottenham : 

 collected by Mr. C. Todd, September 1911. Length 1 inch ( = 20-25 mm.). 



Fig. 1. 



Spermatheca of (a) Limnodrilus longus, [h) L. galeritus, and (c) L. aura7itiacus. 



Segments about 90. Head small. ' Setse 4-6, 7 in the front segments^ the 

 teeth about equal, slender, not coarse like those of L. udekemianus and 

 L. papillosus ; dwindling behind to 3 and 2, with teeth rather wider apart. 

 Chloragogen cells (= intestine) beginning in segment 5. Penis-sheath ve7\i/ 

 long ; duct the longest I have yet observed, with large pyriform prostate and 

 atrium. Spermatheca? somewhat pear-shaped, narrowing gradually (fig. 1 a) 

 into a short duct. Brain somewhat concave in front with convex sides. 

 Not deeply lobed." 



LINN. JOUKN. ZOOLOGY, VOL. XXXII. 10 



