HARDING—ON A NEW LAND-LEECH FROM THE SEYCHELLES 41 
The “posterior organs” described by Miss Lambert as well developed in Philemon 
and less conspicuous in Moquinia, were not observed in J. seychellensis, though it is not 
impossible that they may be detected in fresh material more favourable for examination. 
Somite VIT comprises four rings instead of three, as in Hemadipsa and Moquinia, 
and the nephridiopores begin in the last ring of this somite and so differ as regards the 
position of the first pair from the arrangement described by Miss Lambert in the 
Australian land-leeches; again the ear-like lobes, termed “auricule” by Blanchard, 
which overhang the posterior pair of these pores in most of the Heemadipsinze and form 
a characteristic feature, are absent in Idiobdella. 
I now proceed to give a brief diagnosis of this new genus’ and of the single species 
upon which it has been founded. 
IDICBDELLA, gen. nov. 
[tSu0s strange, peculiar; Bd<AXa, leech. | 
Hemadipsinee with two denticulate jaws. Complete somite formed of five rings. 
Without auricule. No genital apertures in somites XI and XII. 
Idiobdella seychellensis, sp. n. 
The body of this little species has a rough or granular appearance due to the 
presence of small, closely-set papillee disposed transversely on the rings. Posterior sucker 
small and not wider than the widest part of the body. 
Colour (after immersion in alcohol) in three individuals fawn, in the fourth brown, 
uniform above and below. The dorsal surface is traversed by three deep brown 
longitudinal stripes ; two paired rows of large papilla are conspicuous upon the ventral 
surface, a pair of papillee occurring in each “complete” somite upon the third ring. 
Five pairs of eyes situated respectively on rings 2, 3, 4, 5, and 8. 
Rings, 97. Somites I—IV uniannulate, V and VI triannulate, VII with four rings, 
the fifteen somites VIJI—XXII “complete” with five rings, XXIII with four rings, 
XXIV—XXVII uniannulate. 
Anus perforating the groove which separates the last ring from the posterior sucker. 
Nephridia, 17 pairs. The nephridiopores occur, as is usual, in the marginal lines 
of the body, and on the posterior edge of the rings which they pierce; the first pair open 
on the posterior part of ring 14 (the last ring of somite VII); the last pair lie between 
somites XXV and XXVI, whilst the 16th and 17th pairs are separated by six rings, 
instead of five as in the case of the other pairs. 
Genital apertures separated by eleven and a half rings, the male orifice being 
situated between rings 28 and 29, that is to say, between the fourth and fifth rings 
of somite X; and the female orifice lying upon ring 40, namely, the first ring of 
somite XIII. 
Size. The four examples (in alcohol) were in a fairly well extended condition and 
were measured with the following results: No. 1, 13 mm. long and 2°25 mm. wide; 
No. 2, 12°50 mm. long and 2°50 mm. wide; No. 3, 9 mm. long and 2°50 mm. wide ; 
No. 4, 11°50 mm. long and 2:25 mm. wide. 
SECOND SERIES—ZOOLOGY, VOL. XVI. 6 
