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Show 382 MR. F. E. BEDDARD ON TWO [Apr. 17, like excretory tubes in the usual " plectonephric " genera; they give the impression rather of minute pouches opening on to the exterior. A closer survey, however, of their structure shows that there is really nothing anomalous about them. The vesicular layer of cells commonly found attached to the exterior of the tubules is here so largely developed that the appearance referred to is produced. Most of the other characters of the genus are such as are to be met with in other Cryptodrilids. The affinities which they indicate are, however, not very plain. The presence of two gizzards-to commence with perhaps the least important of these characters-is found in the genera Digaster (with which I unite Didymogaster and Perrisogaster of Fletcher), Dichogaster, and Microdrilus. All of the genera mentioned also agree with Millsonia in the diffuse nephridia! system. The last two Cryptodrilids, as well as Typhceus, agree with Millsonia in that the male pores are upon the xviith instead of the more usual xviiith segment. Finally the calciferous glands are, as in Microdrilus, in segments xv.-xvii. The absence of the penial setae distinguishes Millsonia from all the Cryptodrilids mentioned except Dichogaster. Millsonia shows, as I have already intimated, some likeness to the Eudrilids. This likeness, however, is shown only by the species Millsonia nigra. The resemblance consists first of all in the unpaired male pore ; the unpaired genital orifices are not absolutely unknown in the Cryptodrilidae, since they are met with in the genus Fletcherodrilus. But in addition to their being unpaired in the worm now under discussion, there are a pair of terminal muscular sacs which are like the bursa copulatrix of many Eudrilids. The genus Nannodrilus which I describe in the present paper is the only other Cryptodrilid in which there is a similar bursa or rather a pair of them. But I am disposed to consider that the terminal sac which is found appended to the end of the duct of the spermiducal glands in many Perichcetce is tbe homologue of the structure so universal in the Eudrilids. So that the existence of well-developed bursae in Millsonia is not a fact of absolute novelty for the family. Millsonia rubens, n. sp. (Fig. 2, p. 381.) D E F . Length 320 mm.; diameter 12 mm. Number of segments 363. Mcde pores paired. No bursa copulatrix. External characters.-This worm was remarkable on account of its peculiar coloration. In alcohol the front end of the body, in front of the cliteUum, is of a pale violet-grey. The clitelluin itself is of a pale brown. Behind the clitellum the colour is a brick-red, a tint that I have never before seen in any Earthworm. The prostomium is large and does not at all encroach upon the buccal segment. The setae, as already mentioned in the definition of the genus, are very strictly paired; they lie entirely upon the ventral surface of the body. A distance of 2 m m . separates the |
