6 



HA RD WICKE'S SCIENCE- G OSSIP. 



It will be seen from the above description that this 

 Anuraea, which seems to fairly well agree with 

 Ehrenberg's short account of his A. valga, yet bears, 

 in all points, save the unequal lengths of the rear 

 lorica-spines, a very close resemblance to the same 

 author's A. aculeata,. This latter common form, too, 

 is, remarkably subject to variation in this very character 

 of length of posterior spines ; specimens from some 

 localities have these processes equalling in length the 

 rest of the lorica, while others have mere stumpy 

 points (Gosse's var. brevispina) ; and I have myself 

 met with a number of individuals from a well in 

 Bedfordshire in which all traces of these rear spines 

 were totally wanting, yet these were indubitable 

 aculeata, and I was able to demonstrate that the 

 missing spines were wanting in the unhatched young 

 within the egg, as well as in the adult. 



From the foregoing considerations it seems to me 

 that A. valga is only entitled to be regarded as a 

 variety or race of the aggregate species, A. aculeata, 

 since neither in tessellation nor in other respects 

 except the inequality in length of its rear processes, 

 does the former appear to differ from the latter ; the 

 specific identity of the two forms has been indeed 

 already suggested as probable by Gosse. 



But we may, I think, go further. Surgeon Gunson 

 Thorpe has recently described as new a couple of 

 Anuraeas, A. procurva and A.scutata, from Ascension 

 and Brisbane respectively, both of which agree with 

 the form we have just been considering in possessing 

 unequal rear spines to the lorica. Like valga, too, 

 these bear a resemblance to aculeata in their frontal 

 armature and their lorica faceting. Procurva seems 

 sufficiently distinct ; but as regards scutata, while not 

 suggesting that this form of Surgeon Thorpe's is 

 absolutely identical with valga, it seems not im- 

 probable that both will hereafter be found to con- 

 stitute distinct varieties of one aggregate species, 

 aculeata. 



Saccitlus hyalimis, Kellicott. In July 1891, from 

 the same pond as that from which most of my 

 specimens of the Anuraaa, just described, were 

 obtained, viz., on Leyton Flats, I met with numerous 

 individuals of this Sacculus, hitherto known as 

 occurring only in the United States. On one or two 

 occasions since, I have seen a few solitary individuals 

 of the same species, both from the same and neigh- 

 bouring ponds and ifrom Cuckoo Pits, Chingford. 

 I have had them present in the same gathering with 

 S. viridis, so have been well able to appreciate the 

 points of difference between the two species. As 

 regards the anatomy of this creature, I have nothing 

 to add to Professor Kellicott's account published in 

 the "Proc. Amer. Soc. Microsc, 1889," and ab- 

 stracted in the "Supplement;"* the description 

 there given is exact. I am able to confirm Professor 

 Keilicott's cautious statement as to the occurrence 



* "The Rotifera : Supplement, 1889." 



of setae upon the coronal face. He says, "The 

 corona has a circlet of ample cilia, and at the dorsal 

 border there is a conspicuous spatula-shaped apex 

 which, seen laterally, is thin and turned downwards ; 

 on each side of this is what appears to be a stout 

 incurved seta." These words accurately describe 

 what I find on the coronal face of my Snaresbrook 

 specimens. The collapsing of the soft integument at 

 the instant of contraction of the contractile bladder 

 is markedly noticeable. Some of my specimens have 

 but badly merited their specific name, for they have 

 been as crowded with green food as their ally, 

 viridis ; others have been of a clear transparent yellow 

 tint. 



Melicerla pedunadata, Joliet. I have seen one or 

 two individuals of this Melicerta, again from the 

 same pond on Leyton Flats. I made out no 

 character worthy of separating this form from M. 

 ringens, other than the fact that the animal is 

 mounted upon a long non-retractile pedicel, as long 

 as the foot itself, (Fig. 7) similar to that of Floscu- 

 laria longicatidata, and over which the fleshy foot is 

 capable of being retracted by a process of invagina- 

 tion, as shown in the sketch. But this rigid pedicel 

 of chitine, usually of very insignificant length, is 

 frequent among the tube-dwelling rotifera, termi- 

 nating the foot. Melicerta ringens itself possesses it 

 as a short stump with dilated base, (Fig. 8) capable 

 of being easily overlooked. Joliet's name may be 

 retained as indicating a long-pedicelled variety of 

 M. ringens, though Hudson and Gosse omit to 

 mention it in their monograph, even as a synonym. 



Copens Ehrenbergii, Ehrb. This large and handsome 

 rotiferon occurred to me in July 1 892, from the 

 ponds on Leyton Flats, near Snaresbrook. Ehren- 

 berg's figure and description of this form are amply 

 sufficient to identify it ; in my specimens the huge 

 " telegraph-like " auricles were freely projected from 

 the sides of the head as the animals swam at large in 

 a deep trough, and the great "lip" from the ventral 

 face of the corona (quite as large as that figured by 

 Gosse for his C. labiatus), was frequently thrust out ; 

 the mucous investment of the body was also dis- 

 tinctly present. Mr. Western writes me that he and 

 others had previously met with this Copeus at 

 excursions of the Quekett Club to various localities 

 round London, but that he doubts the specific dis- 

 tinctness of this, and Gosse's, form. However pro- 

 bable it may seem that Ehrenbergii and labiatus are 

 but different conditions of one species, due to 

 temporary circumstances of locomotion, our present 

 data are insufficient to justify the inclusion of the 

 two forms under a single specific name, and in any 

 case the name which heads this paragraph would 

 have priority over that of Gosse.* 



Notommata torulosa, Dujardin. Numerous speci- 



* Since writing the above, I hear that this rotifer has been 

 described as British by Mr. W. T. Caiman in the "Ann. 

 Scott. Nat. Hist." for October, 1892. 



