56 



HARDWICKE'S SCIENCE-GOSSIP. 



which is a gap or opening in the cliffs. The collecting 

 here does not differ much from that on the other side 

 of Kingsdown, but Gnophos obscurata and Mclanippe 

 galiata are not uncommon, although rather local. 



From the coastguard station the cliffs again rise, 

 becoming as we advance more and more abrupt, and 

 in some places rising to a considerable height. 

 Great masses of chalk occasionally fall,- blocking up 

 the path and making the walking somewhat rough, 

 but much good collecting may be done here — as before, 

 mostly among the Lepidoptera and Coleoptera. The 

 young botanist will, however, here find many small, 

 but very interesting flowering plants ; the yellow- 

 horned poppy (Glaucium luteum) also occurs on the 

 beach. The young lepidopterist, too, will find plenty 

 of Arge Galathea, Lyccena Corydon, Callimorpha 

 dominula, and Aspilates gilvaria, besides numerous 

 other species more or less common. 



The collecting along this portion of the route 

 derives additional interest from the beauty of the 

 surrounding scenery, having as we walk a fine view 

 of the Channel and vessels of all sizes continually 

 passing on the one hand, and the lofty chalk cliffs on 

 the other. 



As we approach St. Margaret's Bay, a fine view 

 opens out of the cliffs and downs which extend from 

 the other side of the bay towards Dover, the white 

 tower of the lighthouse being just visible above the 

 hills. If the young naturalist has had tolerable sport, 

 he will be glad to rest and refresh himself when he 

 reaches the " Green Man Inn," St. Margaret's Bay. 

 Leaving St. Margaret's Bay and working directly 

 over the Downs towards the lighthouse, the collecting 

 does not differ much from that on the other side of 

 the bay, except that in Lepidoptera several species 

 are wanting here that occur there, while on the other 

 hand a few, such as Satyrus Semele and Eremobia 

 ochrohuca occur here more commonly. 



The wind over the Downs is somewhat of a draw- 

 back to the lepidopterist, taking the insects, as they 

 rise, often quite out of the reach of the collector. I 

 do not think there is very much collecting to be done 

 near Dover, although such rare species as Argynnis 

 lathonia and Driopeia pulchella are sometimes taken, 

 yet they cannot be counted upon. 



MOSS-HAUNTING ROTIFERS; WITH 

 DESCRIPTIONS OF TWO NEW SPECIES. 



By Percy G. Thompson. 



WITHIN the last few years the attention of 

 rotifer-workers has been directed somewhat 

 specially to the numerous forms of Rotifera frequently 

 met with amidst damp moss. These are often quite 

 characteristic of such habitat, many of them are 

 seldom or never met with from the more open 

 conditions of ponds, ditches, etc., and it is scarcely 

 an exaggeration to say that a veritable series of forms 



exists — a sort of rotiferous moss-fauna — eminently 

 typical of this chosen place of abode. 



Nor is it alone among aquatic moss, the Sphagnums 

 and Fontinalis, that these moss-loving rotifers are to 

 be found ; quite a goodly number of species frequent 

 the terrestrial Hypnums and other of the more 

 delicate and feathery genera growing upon old tree- 

 stumps, or upon damp ground, and manage to find 

 sufficient water for their active existence in the slight 

 film retained between the thickly-clustered leaves. 

 A fragment of such growing moss, taken almost at 

 random from a promising tuft, and placed in a trough 

 with added water, will usually within a few minutes 

 be found to be the home of several, perhaps many, 

 distinct species of Rotifera. 



Of the latter, it may be at once stated that a 

 very considerable proportion belong to the Order 

 Bdelloida, comprising those rotifers which (like 

 Rotifer vulgaris) have a leech-like mode of locomotion 

 by alternate elongation and contraction of the body, 

 taking hold by turns with the head and foot at each 

 stride. This predominance in numbers is, of course, > 

 related to the well-known power of resisting drought 

 which the Bdelloids possess in such eminent perfection, 

 and which must very often be called into requisition 

 during dry weather, in the peculiar habit at which 

 the moss frequenters have chosen. But not only 

 Bdelloids, but also many of the true " free-swimmers " 

 ( Ploima), are of frequent occurrence under like condi- 

 tions, and subject to the same variations in, or even 

 temporary failure of, the supply of the important 

 fluid. 



Probably as a direct consequence of such vacilla- 

 tion in their water-supply, nearly all the forms of 

 moss-haunting rotifera are of noticeably small size, 

 and of comparatively insignificant, unattractive 

 appearance, and in many cases require very consider- 

 able study, with high microscopic powers, to 

 satisfactorily elucidate their specific characters. We 

 do not get among them the fine handsome forms, the 

 Brachions, or the Asplanchnas, or the Euchlanis, 

 which love to rove at large in the infinitely greater 

 waters of ponds ; and perhaps for this very reason, 

 and the difficulty experienced in making out their 

 distinctive points, most workers at this class of 

 animals have hitherto more or less avoided the study 

 of the moss-dwellers. But it is just among these 

 insignificant forms, that often will not fit in with the 

 published descriptions so exactly as the observer 

 could wish, that most work remains to be done in the 

 determination of new species, and I need only refer 

 to the recent articles in this paper by my friend 

 Mr. Bryce, to show what is possible in this direction. 



The following short list of Rotifera will serve to 

 indicate those forms which, in my own experience, 

 are most typical of the above habitats. Among 

 damp terrestrial mosses and Jungermannia may be 

 found Macrotrackela conslricta, M. elegans, M. muscu- 

 losa, M. quadricornifera, Adineta vaga, Digletia 



