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On a Neio Rotifer. 123 



cliins close to the stems. At last one got its head into the angle 

 where two stems met, so as to prevent its swimming farther, and, 

 to my dehght, made no attempt to flap itself away in the usual 

 fashion. I at once slipped a circle of ruled glass into the eye-piece, 

 seized my paper, ruled also with squares, and had the good fortune 

 to complete the side view given in Fig. 2 before PedaKon stirred ; 

 when it did go, it went with one bound utterly out of the field. 



The sitting being at an end I had leisure to consider my sketch, 

 and once again I could scarcely credit what I had seen and drawn. 

 Here was a rotifer with six good-sized limbs all worked by muscles 

 contained within them, and terminating in fans of long rigid fringed 

 hairs, more like the extremities of a Dajphnia than those of the 

 rotifers. Many rotifers have one limb — the pseudopodium — which 

 is attached somewhere or other to the ventral surface, and is in 

 Pedalion the grand oar, acting as flapper and rudder, which springs 

 from under the chin. Sijnchseta, too, has a small movable projec- 

 tion at each side of its head bearing its cihary paddles ; but where 

 are the links that connect Sijncliaitas rudimentary stumps with 

 Pedalion s well-formed Hmbs ? It is very possible that such links 

 exist, and may yet be discovered ; for the world of the free-swimming 

 rotifers is a comparatively unexplored one still, and everyone who 

 ventures into it is pretty sure to find something new, even if he can- 

 not hope to rival the achievements of Ehrenberg, Leydig, or Gosse. 



I once caught at Guernsey, in the upper mill-pond at Petit Bot, 

 some rotifers whose ciliated disks were of the shape of the top joint 

 of a thumb, and were densely covered on their ventral surfaces with 

 fine ciha, hke fur, leaving bare only a straight pathway, as it were, 

 through the cilia, in a line with the animals length. 



I am perfectly certain that I never saw the creature before, and 

 I can discover no account of anything like it in the text-books. 

 Unfortunately I delayed one day before I examined and sketched 

 my captives, and on the next they were dead. I returned to Petit 

 Bot for a fresh supply, and found that the miUer had let out the 

 water to clean the pond. 



I have dwelt on Pedahon's external form, partly because I have 

 not yet had time to thoroughly examine its internal organs, but 

 mainly because this rotifer appears to be a weighty witness on the 

 side of those (to wit, Owen, Leydig, Gosse, &c.) who would range 

 the Eotifers rather with the Crustacea than with the Annelida, &c. 

 One of the arguments of Vogt (as quoted by Pritchard) against the 

 Crustacean nature of the Piotifers is that " a pair of jointed locomo- 

 tive organs is never found among the Eotifers at any period of their 

 existence." Xow, as Pedalion has two pairs of such organs, besides 

 its pseudopodium and another limb on the dorsal surface, the above 

 statement must be modified, and the argument will in consequence 

 be considerably weakened. 



K 2 



