592 Transactions of the Society. 



16. Henlea vai'iata Friend. 



As the name implies, this is a very variable Annelid. Indeed, 

 when I first found it I took it to be H. dicksoni, which it greatly 

 resembles at times. But though the two may be found together 

 they are decidedly distinct. I think it necessary to give one of 

 the varieties a special name. A very restless worm, exceedingly 

 difficult to examine. The use of cocaine to reduce activity, how- 

 ever, is often an evil, and one has to be content to tire the worm 

 out by steady observation. 



Length 8-10 mm., with about 40 segments. White or yellowish, 

 full of oval or pointed coelomic corpuscles. Somewhat close set, as 

 distintniished from H. attenuata which was found with it. The 

 setffi vary in number. In the type there are 3-4 dorsally and 5-6 

 ventrally, the innermost being somewhat shorter than the others. 

 In some instances (var. jjolychseia) the setse rise in number to 8-10, 

 varying a little in length as before. There are no oesophageal 

 glands, but a bulb in segment 8 or 9, the dorsal vessel arising in 

 the latter. Gland-cells of girdle closely packed. First pair of 

 nephridia in 5/6. Spermathecfe without glands, ampulla, or 

 diverticula, formed of a simple duct joining the intestine. Often 

 about 3 rows of clear vacuolar glands in tbe epidermis. I failed to 

 find the origin of the nephridial duct in the living worm. There 

 were no salivaries. Brain of the typical Henlean form, about as 

 long as broad, but varying with tension ; concave or nearly straight 

 behind. No setae on the girdle, which extends over 1/3x1-1/2 xiii. 



The variations most noticeable refer to the number of setae, the 

 shape of the brain, the origin of the dorsal vessel, the position of 

 the first pair of nephridia, which are sometimes found in 4/5 — a 

 very advanced position — and the segment in which the oesophagus 

 merges into the intestine. 



British Records. — Eolleston Junction, and Southwell, Notts, 

 March 26 ; Swain's Park, Derbyshire, April 1, 1912. 



o 



17. Henlea attenuata Friend. 



Though no adult specimen has yet been found, there can be no 

 doubt about the species. I have examined a large series of speci- 

 mens, and have found it in thi'ee localities. 



Length 6-10 mm., very attenuated. Segments 35-40. Pure 

 white to the naked eye, but with yellowish-brown intestine under 

 the Microscope. Brain straight or sUghtly concave behind, about 

 1^ times longer than broad. Short salivary glands, sac-like, un- 

 braiiched (fig. 115), arising from the oesophagus midway between the 

 pharynx and first pair of septals. Setae 3-5, very slightly curved, 

 but not hooked. Blunt inner extremity but pointed exterior. One 



