52 MR. F. E. BEDDARD ON [Feb. 4, 



3. Observations upon an American Species of Pericheeta, 

 and upon some other Members of tlie Genus. By Frank 

 E. Beddard, M.A., Prosector to tlie Society. 



[Received December 23, 1889.] 



(Plates IV. & V.) 



Some weeks since Mr. C. Bartlett brought me two hving earth- 

 worms, which he had found in earth surrounding the roots of an 

 orchid, received from South America. One of these was a very 

 small example of a Lumbricus, which I have not yet identified ; the 

 other was a Perich<eta, which is illustrated in the acconipanyina; 

 coloured sketch (Plate IV. fig. 1). There are so very few coloured 

 figures extant of foreign earthworms' that I have considered it 

 desirable to put oii record the coloration of this species, wliich 

 appears to be P. indica. The worm is remarkable for its extreme 

 activitv, as has been already noted by Baird (1) and by Perrier (18) 

 in other species of Perichceta, studied in the living condition. 

 Another curious characteristic of the worm is its method of pro- 

 gression ; many Oligochaeta seem to make use of the mouth in 

 locomotion, attaching themselves firmly by it, while the following 

 segments are moved forwards ; in the present species a considerable 

 portion (? the whole ) of the buccal cavity is everted whenever the 

 animal moves, so that the head has a remarkably leech-like aspect. 

 I have attempted to illustrate the appearance of tlie anterior end of 

 the body during locomotion in the accompanying drawings (Plate IV. 

 figs. 2, 3). I never observed the worm in motion without this alternate 

 eversion and inversion of the buccal cavity. 



As will be seen, the colour of the worm is a rich brown, somewhat 

 darker upon the clitelluin, with a whitish line in the middle of each 

 segment. Tlie colour appears to be caused by at least two distinct 

 pigments; one or more of tlie.se is dissolved out bv alcohol, leaving 

 the worm colourless, except for a dark bluish-brown area along tiie 

 back (which resists the action of the spirit), and is recognizable in 

 sections as black granules lying in the epidermis and in the circular 

 muscular layer. I lay particular stress upon this fact, for the reason 

 that in other specimens of P. indica (see no. 5), which I received 

 from New Caledonia and which were sent to me in alcohol, the 

 brown coloration and the whitish line in the middle of each segment 

 are preserved. It is interesting to find that P. indica, which has 

 been already recorded from the East Indies and from New Caledonia, 

 occurs also in South America. There are not many species which 

 have so wide a distribution ; P. affinis, P. houUeti, and Urochceta 

 corethrurus, however, are forms which inhabit the tropics of both the 



' The only coloured figures known to me (taken from life) are several 

 of Penchxefa and Hypog<son by Scbraarda (20)> and of Microchceta rapjiii in a 

 paper by myself upon the anatomy of this worm (3) ; Schiuarda's figures lose 

 Bomeof their value from the fact that they are not accompanied by any deBcrip- 

 tiou of the internal characters, and cannot, therefore, be easilv identified. 



