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Show 1892.] SPECIES OF EARTHWORMS. 681 The setae are strictly paired and are on the ventral surface. There are two gizzards, whose exact position I a m not able to state. The calciferous glands are kidney-shaped ; there are three pairs of them, in segments xv., xvi., xvii. The intestine commences in the middle of segment xviii. The dorsal blood-vessel is single; there are three pairs of hearts, in segments x., xi., xii. Six septa following the gizzard are thickened, but their increase in thickness is not so well marked as it often is in Earthworms. The internal anatomy of this species is precisely like that of Benhamia crassa above described ; the form of the penial setae, which are the only structures by which some of these Benhamice can be distinguished, were hardly different from those of Benhamia crassa ; in the specimen from Dominica they were even twisted into a spiral at the extremity, there were possibly rather more denticulations on the end ; in the same way the end of the two vasa deferentia of each side were enclosed in a common muscular sheath. It may be that the glandular caecum of the buccal cavity will prove to be a character of generic value. I followed out the ducts of the mucous gland, and find that each gland opens into the pharynx by a wide aperture, which has, however, a shorter duct than in Octochcetus multiporus; the opening is also situated further back than in that genus ; besides the opening into the buccal cavity, the mass of nephridial tubules, which I have called the mucous gland, also open on to the exterior by numerous openings. 1 should mention that in this species, as in B. crassa, the last pair of hearts is in segment xii. 8. Benhamia crassa, n. sp. Among a number of living Earthworms lately received from Kew, whither they had been accidentally transported from Lagos, West Africa, were two very small individuals, measuring about an inch in length after preservation, which apparently belong to two distinct species. Their appearance while alive was so very similar that I regarded them as of the same species, and proceeded therefore to examine one by means of a series of longitudinal sections, while the other was cut into two halves and the viscera teased out. I had hoped in this way to supplement by one method of study the results obtained by the other. The two individuals, however, turned out to differ in a slight degree, the difference being possibly of specific value; the difference mainly concerned the extent of the clitellum ; in other points they appeared to agree. The prostomium is imbedded in the buccal segment, but it is not continued by grooves over any part of this segment. The dorsal pores begin between segments v./vi. if not earlier. The clitellum commences in the hinder half of segment xiii., and extends until the xxist segment ; only on the thirteenth segment is it developed over the ventral as well as the dorsal and lateral surfaces; in the remaining segments there is an area, occupying the whole of |
