234 



KNOWLEDGE. 



June. 1911. 



The instrumental record showed that the balloon had 

 reached an altitude of 19-1 kilometres or sixty-two thousand 

 feet. The lowest temperature recorded was 214°- 5 (absolute 

 scale) at a height of thirty-three thousand feet. The 

 temperature then increased to 224^-5 at thirty-nine thousand 

 feet, but fell again to 21S°-0 at the maxinumi height. 



By 



MICROSCOPY. 



A. W. Shepp.-\rd, F.R.M.S., 



with the assistitiicc of tlic folloic'ing inicroscopists :- 



AUIML'R C. HANFItMJ- 



Thk Rkv. E. W". tJ<.)\i'KLL. M..\. 



jAMtb BlRTON. 



Charles H. Cakfvn. 



C. D. Soar, F.R.M.S. 



.■\RTHLR EaRLAMi. E.R.M.S. 



Richard T. I.hwt!,. F.R.M.S. 

 Chas. F. Rolssklkt, F.R.M.S 

 D. J.ScoiRHELD. F.Z.S., F.R.M.S. 



Figure 1. 

 Nc!iiJi(7iiia tn\niiiii!aris. Female, ventral surface. 



NOTE ON A \VAT1:K-MITE NEW To BRITAIN 

 iXEUMANIA TRIANGULARIS PIEKSK',).— In 1908 

 both sexes of the above mite were taken from a fresh- 

 water pool in the locality of Stourbridge, Worcestershire. 



The female is 1-42 millimetres long, of a pale yellow colour. 

 Epimeral plates are finely granulated, the fourth pair having 

 a well-marked hook-shaped process at their lower extremity. 

 The genital plates are green in colour, with thirty to thirty- 

 five acetabula on each, .\bove each plate are three small hair 

 pores arranged somewhat like the apices of a triangle in outline, 

 together with a prominent gland. Legs are yellowish-green 

 in colour and all supplied with strong spines or swimming 

 hairs, the second and fourth pairs having in addition a number 

 of feathered or serrated hairs presenting a pretty effect under 

 dark ground illumination. 



The male is smaller than the female, 1-12 millimetres long, of 

 a light .almost transparent yellow colour. The Malpighian \ essel 

 is very distinct. Genital plates are circular in outline, of a pale 

 green colour, with about twenty-five acetabula on each half and 

 several fine hairs at top and bottom. Two prominent glands 

 on each side of median line, one towards margin of body. 

 Several species of this genus are described by Mr, C, D. Soar in 

 Scicticc Gossip, Vol. \'II. p. 19 under the generic name 



Cochlcoplionis. 



G. P. Deklev, 



UN THE 1D1:NTITV OF HABROTROCHA BIDHXS 

 (GOSSE), — If the recognition of this handsome and graceful 

 Bdelloid depended solely upon the original description 

 ("Catalogue of Rotifera found in Britain," P, H, Gosse, Ann. 

 and Mag. Nat. Hist., 1.S51I, it could only be regarded as 

 hopeless, for the few characters then stated liave proved to 

 be common to many distinct forms,-- Fortunately, however, 

 Gosse found opportunity in "The Rotifera" (Hudson and 

 Gosse, 18S6), to provide a fuller description accompanied by 



figures which, if wanting in detail, give a fair idea of the 

 general style of an animal which seems to be somewhat of a 

 rarity. In about twenty years' experience I have only met with 

 it on two occasions, vi^. : in ground moss kindly collected for 

 me by Mr. D. J. Scourfield near Bury St. Edmunds, and from 

 roof moss which I obtained from an accessible roof-gutter 

 near Mundesley, 



But before finding, in 1908, the particular form which I am 

 confident is that seen by Gosse, I had repeatedly compared 

 with his description other two-toothed blind Philodinidae, 

 always with unsatisfactory result. That others may avoid 

 the like tedious proceeding, it may be useful to point out the 

 more distinctive details suppHcd by Gosse, and to give some 

 additional characteristics which will further establish a very 

 interesting species. 



The corona and the body outline of my specimens were 

 generally in agreement with Gosse's figures, and they also 

 possessed the wild manners, the small two-toothed rami, and 

 (occasionally) the angular lateral prominence which he 

 described. But the most unusual detail, and. therefore, the 

 best for purposes of identification, was the constantly 

 recurring display of the central toe. short and acute, between 

 the spurs, as shown by Gosse in his figure of the imperfectly 

 retracted position, a pose of the toe and spurs characteristic 

 also of Habrotrocha tripiis (Murray I. but elsewhere unknown 

 among blind three-toed Philodinidae. Gosse describes the 

 foot as having a small stiff point behind and two soft 



Figure 1, 

 Head with corona (dorsal view). 



ce 



Figure 2. 



Extremity of foot 

 (ventral view). 



5_ l/V\'^ 



/ 



CE 



Figure 3. 



Anal segment 



and foot 

 (dorsal view). 



cylindrical lateral protrusible toes, truncate at the extremities. 

 I do not seem to have seen the truncate ends of the lateral 

 toes, but the central toe was frequently visible as a small stiff 

 point behind, 



Gosse's description of the stomach is also noteworthy. In 

 one of his specimens it ;ippeared to be composed of a number 

 of spherical cells, but in others was of a minutely granular 

 texture. These varying appearances of the stomach are quite 

 usual with several species of the "pellet-making" Philodinidae 

 and depend upon the quantity of digestive fluid between the 

 two membranes of the stomach wall. When the fluid is scanty 

 the food-pellets within the stomach cavity are plainly visible, 

 ■and have the appearance of spherical cells. When the fluid is 

 abundant, its finely-granular consistence is sufficiently opaque 

 to completely hide the actual contents of the stomach, I 

 believe, therefore, that Gosse's description of the stomach 

 indicates that his species was a pellet-maker and in this 

 respect .also my specimens agreed with his, Habrotrocha 



