Descriptions of Earthworms

During his last journey in Liberia, my colleague Mr. Büttiköfer had the opportunity to collect a number of earthworms under a mouldering palm-tree. Among them I met with some specimens of Ac. Büttikoferi, a species which I briefly described in this Journal, Vol. VI, p. 105. However this description being based upon the examination of a single very badly preserved individual, I wish to give in the following note some illustrations and a more full account of the distinguishing characters of this species. The number of described species of Lumbricidae from all parts of the world is increasing daily, and it is a wellknown fact to every-one, dealing with this matter, that it is hardly possible to determine the systematic position of earthworms only by their external features; therefore I believe it to be an absolute necessity to indicate accurately not only their external but also their internal characters. In all our specimens the clitellum is very apparent, extending from segment 13 (14) to 19; it is distinguished from the remaining part of the body as well by its darker colour, as by the pronounced glandular integument of its segments. However at its ventral side there is a small area without glandular development, bounded on each side by a narrow groove, that runns from the genital pore on the 17th segment to that on the 19th ring. Each segment is divided by two transverse grooves in three annuli, the median of which is elevated as a ridge and bears the bristles; the longitudinal diameter of a segment in front of the girdle is as large as that of three segments behind it. The dorsal pores appear to commence behind the clitellum.