9 2 



HA RD WICKE S SCIENCE- G OSSIP. 



(p. 69). The white Cephalantheras (Epipactis, Sow.) 

 could hardly be mistaken for E. palustris (marsh 

 helleborine). The only doubt with regard to the 

 plant under consideration can be whether it is the 

 C. grandiflora or C. ensifolia ? I believe it to be 

 the latter, because of the narrow leaves and minute 

 bracts ; at the same time I only have the dried 

 specimen as forwarded to me. I have before me a 

 series of both species, gathered at Raveno, Maggiore, 

 some years ago. The leaves of C. grandiflora are so 

 much broader and the bracts more prominent than 

 with C. ensifolia ; the flower-spike of the latter is 

 smaller, with a few loose flowers. But when I come 

 to study the whole series, some variety is noticeable 

 in the different specimens ; the two species appear to 

 run gradually into each other. As a matter of fact I 

 believe neither C. grand/flora nor C. ensifolia have 

 been recorded from the Isle of Wight. " Woods of 

 the Undercliff " was a near enough locality for my 

 purpose, but I may add the information that the 

 character of rock is chalk marl at the precise spot. 

 May I take this opportunity of stating that the rare 

 Swertia was found in the north of England last 

 summer ? I dare not say more, except that I saw it, 

 and that it shall not be exterminated through me. — 

 C. P. 



GEOLOGY, &C. 



The Cambridgeshire Chalk. — An important 

 paper on this subject has just been read before the 

 Geological Society by Mr. W. Hill, F.G.S. The 

 author, giving a description of the Middle Chalk seen 

 in the cliffs east and west of Dover, stated that the 

 grit bed of Mr. Price, though much thicker, had all 

 the appearance and structure of the Melbourn Rock, 

 and this, with less hard, but still nodular, chalk 

 above, appeared to be the equivalent of the zone 

 of //. Cnvieri in Cambridgeshire. The zone of 

 Terebratulina gracilis is well marked in the Dover 

 cliffs, and is equal in thickness to that zone as 

 described in the Cambr. Mem., viz., 150 feet. 

 Above this zone the chalk became harder, withered, 

 with lumpy projections, and finally passed into a 

 series of rocky layers, separated by courses of softer 

 chalk, containing, however, hard crystalline lumps. 

 The passage to this rocky chalk was marked by the 

 occurrence of Ilolaster planus (zone of H. planus). 

 The rocky layers, extending upward of 80 feet, were 

 marked by the presence of numbers of Micrasters, 

 " Chalk with many Micrasters " of the author. His 

 division included all the nodular chalk of Dover, the 

 " Chalk with many Organic Remains " of W. Phillips, 

 and in it were found the fossils recorded as peculiar 

 to chalk rock in the Geology of Cambridgeshire. It 

 appeared divisible into two zones ; the lower 15 feet, 

 with Micraster brez'iporus (zone of J/, breviporus) 



may be considered by some to be an extension of the 

 zone of H. planus, the form which marks the passage 

 from the soft to the hard chalk. In the remainder 

 M. cor-testudinariuni was common (zone of M. cor- 

 testudinarium). Seen in thin sections under the 

 microscope, the structure of the hard beds which 

 mark the limits of the Middle Chalk was stated to 

 be very similar. In conclusion, the author con- 

 sidered that the divisions of the Middle Chalk, as set 

 forth in the Cambr. Memoir, are well shown in the 

 cliffs of Dover ; but the hard beds, which appeared to 

 him the equivalent of the Chalk Rock, and mark the 

 upper limit of Middle Chalk, attaining a great 

 development at Dover, it became necessary to 

 examine the palseontological position of that bed, to 

 which the name ' ' Chalk Rock " was given by Mr. 

 Whitaker. Having studied Mr. Whitaker's descrip- 

 tion given in the " Geology of the London Basin," 

 and the exposures of this rock between Cambridge 

 and the Thames, he drew the conclusion, that there 

 was probably more than one bed to which the name 

 Chalk Rock might be applied, and that these, prob- 

 ably not all persistent, may occur at different 

 palaeontological horizons. He therefore proposed 

 to take the zone of H. planus as the top of the Middle 

 Chalk ; although this zone was difficult to identify 

 inland, from the paucity of its fossils, the base of the 

 overlying zone was well marked by the abundance of 

 Micrasters and other forms, which appeared to him 

 more closely allied to Upper than to Lower Chalk. 

 He believed that while the Chalk Rock seen at Henley 

 may be considered the summit of the Middle Chalk, 

 the Chalk Rock of Cambridgeshire, though convenient 

 for marking the summit of the Middle Chalk of that 

 county, included that which was really the upper 

 part of the zone of H. planus and the base of the 

 true Upper Chalk, the equivalent of Chalk with many 

 Micrasters of Dover. He would therefore consider 

 the Middle Chalk of Dover to be that included from 

 the base of the grit-bed to the summit of the zone of 

 H. planus. Its thickness was 242 feet at Shake- 

 speare's Cliff. 



The Geologists' Association. — No. 4 of vol. 

 ix. of the "Proceedings" of this society is pub- 

 lished, containing accounts of no fewer than seventeen 

 excursions. These accounts are always well, although 

 sketchily, written, and many of them are illustrated 

 with diagrams of the geological sections of the 

 districts visited. These excursions begin at Easter 

 and last till August, and are usually taken on 

 Saturdays and Bank Holidays ; but in July there is 

 a week's holiday to some special place of geological 

 interest at a distance, when large gatherings of 

 members usually attend, so that the "long excursion," 

 as it is called, is one of the most delightful of summer 

 holidays. The monthly meetings are held from 

 November to July inclusive, when papers are read 

 on subjects relating to geology, followed by dis- 



