74 



HARDWICKE'S SCIENCE- GO S SIP. 



stature, but they still bear a strong family likeness 

 to their congeners of the plains. Examples are 



Linaria alpina Phyteuma hemispbseri- 



Globularia nudicaulis cum 



and cordifolia Coichicum alpiuum 



Teucrium pyrenaicum Gagea Liottardi 



Ononis cenisia Astragalus monspessu- 



Ceriuthe alpina lanus 

 Helianthemum canum 



The great genera Primula and Gentiana should be 

 included in this class. They have very few repre- 

 sentatives in the Arctic regions, and attain their 

 maximum development in the great Alpine chain, 

 but at the same time they are well represented in 

 the plains, whence probably they originally came. 



With regard to the origin of our second class 

 (the largest and most important), we ought to state 

 that a different theory to that whicb we have given 

 is also held, especially by some German botanists. 

 They consider that the great centre of dispersion 

 was from the Altai mountains, in Siberia, and not, 

 as we suppose, from the Arctic regions of Europe. 

 The principal argument in favour of their view is 

 that many Alpine plants are represented in Siberia 

 which are wanting in Arctic Europe ; but this may 

 be accounted for when we remember that the great 

 variety of climate and soil in the Alpine chaiu 

 would cause the development of fresh species, 

 while the parent stock in Arctic Europe would 

 remain comparatively stationary. And although it 

 is true that some species which are found in Arctic 

 Europe, as Cornus sitecica, Rubiis arcticus and 

 chamcemorus, Diapensia lapponica, and Nardosmia 

 frigida, are met with again in Siberia only, it is to 

 our mind easier to suppose that these plants were 

 dispersed from Arctic Europe, in the direction of 

 Central Asia, by glacial action, than that they 

 formerly existed in the Alps of Europe, from thence 

 colonized the North, and afterwards became extinct 

 in the Alps. T. Howse, E.L.S. 



ELOSCULARIA TRILOBATA. 



By E. Collins, M.D. 



■jl/rR. CUBITT'S remarks in the July number of 

 -^*-'- the Monthly Microscopic Journal on my paper, 

 published in the January (1872) number of your 

 periodical, call for a few words from me. 



In the first place, it was only on reading Mr. 

 Cubitt's paper a few days ago that I first became 

 aware of the fact that Mr. Tatem had previously 

 aescribed the large pelleted Melicerta* M. pilula, 



* Mr. Gosse, to whom I sent specimens in 1865 and 1866, 

 recomm nded me to name this species M. coprodoma, from 

 KOTrpoQ, dung, and Sejiii), to build, from the fact that 

 this creature builds its tube with its own excrement. This 

 would, probably, be a better name than either pilula or 

 socialis. 



or, as I named it, M. socialis, in a communication 

 read before the Quekett Microscopic Club in 1868. 

 As I feel, therefore, that some apology is due to 

 Mr. Tatem, I hope that he will consider a residence 

 abroad, from early in 1807 to the end of 1869, a 

 sufficient excuse, from me, for having overlooked 

 his paper. 



In the second place, with regard to Floscularia 

 trilobafa, I cannot allow, as Mr. Cubitt asserts, that 

 this is a " pseudo-new species," and identical with 

 F. campanulata, for they differ in many respects, 

 the most prominent distinguishing feature being the 

 arrangement of the disk, which in the latter is never 

 divided into less than five lobes ; at least such is 

 ray experience, and that also of every author whose 

 descriptions of this rotifer I have read, while in 

 the former the number of lobes never exceeds three. 

 The lobes, moreover, in F. trilobata are larger, better 

 defined, and have wider and more marked depres- 

 sions or spaces between thein ; the creature itself 

 is much larger, and differs also in its general con- 

 figuration ; its tube, too, is probably more frequently 

 absent than present ; and I have never seen it occu- 

 pying so large, solid, and well-formed a tube as 

 Mr. Cubitt in his drawing represents F. campanulata 

 to inhabit. 



I first discovered F. trihhata in 1865 (my ac- 

 quaintance with the large pelleted Melicerta bears 

 the same date), and, being unable to identify it with 

 any of the described species, I wrote to Mr. Gosse 

 on the subject, and after some correspondence was 

 enabled to furnish him M'ith a specimen. He, after 

 careful observation, concludes a letter to me, dated 

 October, 1865 (having first remarked on the number 

 of lobes, &c., and compared it with F. campanu- 

 lata^, " And so yours is, no doubt a new species, as 

 you conclude. My specimen, that you sent me, has 

 laid an ^^g in the live-box, and so is certainly adult." 



I believe this species to be very rare. I do not 

 suppose I have seen many more than twenty speci- 

 mens, but have had the opportunity of observing it 

 from its infantile stage to old age and death. All 

 my specimens were taken from one small pool in 

 the parish of Sandhurst, Berks, which abounds in 

 rare and interesting Rotifera. I have searched for 

 F. trilobata, with a friend, in all the neighbouring 

 pools and streams repeatedly, but invariably without 

 success. Whether this pool is still in existence or 

 not I cannot say, for it is now some six years since 

 I quitted that neighbourhood. 



It seems necessary that I should conclude by 

 stating that my former paper was written simply 

 for the purpose of placing on record the existence 

 of certain species of Rotatoria that I believed to be 

 undescribed. 



"It is only ignorance that sneers at a pursuit 

 because the latter deals with common - place 

 objects."— T't^j/Zor's " Half -hours at the Seaside" 



