| OCR Text |
Show 674 MR, F. E. BEDDARD ON NEW [Dec. 20, doubt, to extrude the papillae already spoken of, on to which the atrial pores open. There are no penial setae. This species is clearly most intimately related to Octochcetus multiporus; indeed it is not a little difficult to separate the two; the difficulty, too, is increased by the variability of the larger species. This difference of size is the most obvious difference ; and it is, I think, a difference that must be allowed. The variability of Octochcetus multiporus unfortunately concerns those very organs upon which I had at first attempted to lay stress as distinguishing the two. In some individuals of Octochcetus multiporus the gizzard is limited to the sixth segment, the second septum lying just in front of it, attached therefore to the oesophagus ; but in other specimens this septum is inserted on to the gizzard itself, which thus occupies two segments, as in Octochcetus thomasi. In two individuals the single pair of calciferous glands are in segment xviii.; but in others, as is the case with Octochcetus thomasi, in the xviith. Another possible distinction between the small and the large species concerns the dorsal vessel ; in O. thomasi, as already mentioned, this vessel is single until the seventh segment. In a specimen of Octochcetus multiporus the dorsal vessel was single until the commencement of the sixth segment only ; in this segment it became double; in another the single dorsal vessel became double at the septum separating v./vi., but immediately after the two halves became fused, to again divide at about the middle of the segment. The shape of the gizzard and its relative length in the two species does appear to differ; in the smaller species it is proportionately longer and narrower than in the large species. The next new species cannot by any possibility be confounded with the foregoing; I name it after Capt. Hutton, who has done so much in describing the fauna of N ew Zealand. 2. Octochaetus huttoni, n. sp. I had a number of examples of this species sent to me by Mr. W . W . Smith; they were all of approximately the same size; an individual selected for accurate measurement was 130 m m . in length by 7 m m . in breadth at the clitellum. It consisted of 233 segments. The colour during life was pink, the clitellum being white ; this colour is due to the fact that the species, like 0. multiporus, had no pigment in the skin. The anterior segments are much annulated. After the clitellum there is also, though to a less extent, an annulation of the segments. The clitellum occupies segments xiii.-xix. (xx.). The atrial pores are borne upon a very prominent fold overhanging on each side the ventral surface, which in this region appears in consequence as if hollowed out. The two pores of each side are connected by a longitudinal furrow. The prostomium is short and wide, and is not continued by grooves on to the buccal segment, which is marked by numerous furrows. The setae are in pairs not closely approximated. |
