73 i Transactions of the Society. 



intersegment 4 5. Sometimes well marked glands are to be found 

 at the orifice or along the duct, but in the present instance I 

 found no such glands, nor were any diverticula present. The 

 organ appears somewhat bottle-shaped, with the narrow neck 

 towards the intestine into which it opens. 



As it is proposed to follow this study with descriptions of other 

 new species, it has been thought advisable to go somewhat mote 

 into detail than will be necessary in later papers. A few figures 

 are added to make some of the points intelligible to those readers 

 who have not heretofore given the Enchytrseids any attention. 



II. — Fridcricia Peruviana sp. n. 



On May 13 I received from Kew Gardens a small quantity 

 of earth, containing two young Annelids, from Peru. The mould 

 had come with some plants in Wardian cases, and I kept it for 

 some days to see what other specimens of interest might reveal 

 themselves. On Whit Monday, while I was subjecting the material 

 to more careful examination, I found a small Enchytiadd which. 

 presents so many interesting features, and is so different from any 

 other species yet known to me, that I have ventured to regard it as 

 a new species. As there seems no reason to suppose that it got 

 into the mould after reaching this country, and as it is a well- 

 marked Fridericia, I have not hesitated to name it after the country 

 whence it seems to have reached England. While there are one or 

 two Fridericias which approach.it in certain characters, there are, 

 on the other hand, various points of association with Henlea and 

 Buchholzia, as will be seen when the diagnosis is complete. In 

 size, average number of setae, and one or two other particulars, it 

 approaches Fridericia parva Bretscher ( = F. Bretseheri Southern), 

 a species which has already been found in Switzerland, Scotland, 

 and Ireland. But the differences are at the same time great and 

 important. 



The new species is 5-6 mm. in length. The intestine from the 

 8th or 9th segment backward is covered with brownish cells, which 

 render the animal somewhat opaque. The ccelomic corpuscles are 

 large and numerous, so that it is very difficult to see the nephridia. 

 These corpuscles instantly break up upon being forced out of the 

 body, indicating that they are surrounded by an unusually delicate 

 membrane. The nephridia are lobed, and the main portion is post- 

 septal. The anus is terminal, very glandular and sensitive, with a 

 large aperture of striking structure. It appears to be composed of 

 four large ilaps, or valvular flanges, closely resembling those of 

 Dero obtvsa, which seem to indicate that the worm may live in a 

 habitat where a specially constructed posterior is of value, perhaps, 

 for purposes of aeration. Consequently there are no setee on the 

 two hind-most segments. The setse range from two to five in 



