52 Mr. R. Templeton's Description 



jected, its restoration may be confidently expected with tlie first 

 good monograph which appears from our foreign fellow-labourers 

 in this branch of scientific research. 



I found nothing among the oral appendages which bore the 

 slightest resemblance to a lip, but near the rostrated part beneath 

 is obviously the opening into the pharynx ; when the Xenos lay 

 upon its back I saw plainly down into it, parts of the interior 

 rising into view as I elevated the platform of the microscope; the 

 edges were corrugated, as if the orifice was capable of considera- 

 ble change of size and form, and resembled much the mouth of 

 the polypi. I was much struck with the thinness and lancet-like 

 appearance of the mandibles, and with their peculiar articulation, 

 with the lateral plate descending from the ocular pedicle. The 

 whole inferior surface of the head, from the rostrum to the fore 

 legs, was found to be membranous, and to be thrown into folds in 

 various motions of the head. 



An error seems to have arisen and been repeated by every one 

 who regarded these little creatures through Mr. Bauer's eyes and a 

 compound microscope ; — it consists in supposed vesicles cushion- 

 ing the tarsus, or a " vesicular membrane capable of being in- 

 flated," and the quaint appendix of Kirby, of " the fact of their 

 inflatibility not being ascertained," appears likely to rank some 

 time longer among desiderata. The fact is, all the joints, but 

 especially the terminal, are lobed ; and when seen from above, a 

 membrane is observed to extend itself some way in advance of 

 the lobated extremities, and being thin and transparent, suggested, 

 when the outlines became mellowed in the field of a compound 

 microscope, the idea of a vesicle ; but when viewed laterally, the 

 truth becomes at once apparent ; besides being lobed, the joints 

 are arched transversely; and from within the concavity, and I do 

 believe from an articulation, an appendage of very similar form, 

 not however lobed, passes in advance of the joints; it is very thin, 

 its edges carrying strong spinelike hairs, which also cross the 

 hollow inferior surface in rows, and it is on these the animal is 

 sustained in the quiescent state. 



There appeared to me no sufficient reason for the division of 

 the antitrunk into distinct collars or rings, which I think I re- 

 member to have seen in sketches from dead specimens; the plates 

 are not continuous round the trunk, but are separate, and united 

 by a tough leathery-looking membrane, in many places thrown 

 into folds, which are not permanent, but made to disappear on 

 moving the head or adjoining plates. 



When I proceeded to the examination of the pupa, I disen- 



