176 W. B. BENHAM. 



recently further extended the genus Anteus to include 

 Urobenus; but it appears to me that the characteristic in- 

 testinal caeca in Somite xxvi, as well as the peculiar shape of 

 the oesophageal glands, the pyriform glands, the absence of 

 ornamentation in the chsetse, and other features, are sufficient 

 to separate the two genera: his Anteus papillifer is 

 undoubtedly Urobenus. I would, therefore, still retain the 

 three genera Anteus, Rhinodrilus, and Urobenus as 

 distinct. 



EXPLANATION OF PLATES XIX & XX, 



Illustrating Dr. Benham^s paper on " A New English Genus 

 of Aquatic Oligochseta (S parganophilus tamesis) 

 belonging to the Family Rhinodrilidae." 



Fig. 1. — Dorsal view of Sparganophilus tamesis; enlarged twice. 



JFiG. 2. — Ventral view of the anterior end of the worm ; enlarged twice. 



Fig. 3. — The hinder end of the worm, dorsal view, to show the elongated 

 pjgidium ; much enlarged. 



Fig. 4. — Two cocoons ; natural size. 



The figures 1, 2, 3, 4, are lithographed from coloured drawings retained in 

 the author's possession. 



Fig. 5.— a chseta. Note the ridges. 



j'iG. 6.— The worm dissected from above, intended to exhibit chiefly the 

 vascular system. The nephridia are omitted. Com. v. One of the commis- 

 sural vessels, which occur only in the anterior somites. Dors. v. Dorsal 

 blood-trunk. D. teg. v. One of the tegumenlary vessels arising from the 

 dorsal trunk, and repeated metamerically throughout the body behind Somite 

 XIII. Their relations to the septa are not accurately shown (see Figs. 8 and 

 10). heart. One of the five lateral hearts. Int. Intestine, commencing in 

 Somite ix. Long. teg. v. The longitudinal tegumentary vessels arising from 

 the tegumentary vessels of Somite xiv : that connected with the ventral 

 vessel is in outline, ces. Oesophagus. sal. gl. One of the three pairs of 

 salivary glands, splh. Spermatlieca. V. teg. v. One of the ventral tegumen- 

 tary vessels. 



