140 Transactions of the Society. 



nepliriclia in 4/5 ; postseptal large, duct not proceeding from pos- 

 terior extremity. Brain incised behind, length about 1^ width. 

 Spermathecre very unusual, appearing to combine dorsally so as 

 to form an unpaired ampulla. Ccelomic corpuscles oval, not horny. 

 . The characters are intermediate between those of Marionina 

 and Henlca, on which account the specific name has been chosen. 

 1912, Friend, in Trans. Notts Nat. Soc, pp. 59-60. Found be- 

 tween Burton Joyce and Lowdham, December 16, 1912. 



Owing to the large number of species of Henlea now found in 

 Great Britain, 1 have found it desirable (9) to divide them into 

 two groups, reserving the name Henlea for those which possess 

 oesophageal glands, and calling the others, which are destitute of 

 such glands, Hcyileanella. 



8. The Genus Fridericia. 



The members of this genus are very numerous, and in most 

 instances can be readily distinguished from other genera by their 

 setse and spermathecse. When the setse number four or more per 

 set, the innermost are the shortest. In many cases the sperma- 

 thecse are possessed of diverticula, and the brain is almost invariably 

 convex behind. To differentiate the species, however, is by no 

 means an easy task, since their number is now rapidly approaching 

 a hundred. In Great Britain alone we have now some forty 

 known species, and every year the number grows. I have already 

 in this Journal (1) shown how they may be conveniently tabulated. 



Fridericia arborea sp. n. 



Length 6-8 mm. Segments 35-40. Front setse two, rarely 

 three dorsally,3-4ventrally, small ; three stronger ones in the middle 

 and two in the final segments. Brain of the typical shape, but in 

 some cases tending to concave behind, with underlap. Salivary 

 glands extending to 5/6 with long forked ends. First pair of 

 nephridia in 6/7. Dorsal vessel arising about the 15th segment. 

 Ccelomic corpuscles of two kinds, the larger oval. Three pairs of 

 septal glands. Girdle on 12 to balf 13. Spermathecse with duct 

 roughly covered with small cellular outgrowths. I found two 

 forms. The first has the brain slightly concave behind, and the 

 duct of the anterior nephridia short; while the second has the 

 brain convex before and behind, and long ducts to the nephridia, 

 opening by large glandular pores. The species belongs to the 

 bulbosa group. The members of this section are numerous and not 

 easy to distinguish on paper, though presenting very clear charac- 

 teristics under the Microscope when alive. The first was found in 

 a decaying tree trunk at Zouch Mills, Notts, April 2 ; the second 

 form at Mapperley, May 14, 1913. 



