42 Reports & Proceedings — Geological Society of London. 



described in which occurred a fallen mass of a coal-seam which had 

 been large enough to work ; fragments of charred wood and rounded 

 pebbles of biotite, hornblende, and augite also occur in this neck. 

 In another case marine shells — of a type not later than Millstone 

 Grit — had been found in the ash of a neck, probably washed into the 

 crater of a submarine volcano or into one on low-lying ground liable 

 to submergence. This phase of volcanic activity probably started 

 soon after the deposition of the Lower Carboniferous Limestones, and 

 continued intermittently till Millstone Grit times, with quiescence 

 during the deposition of the Coal-measures ; but farther to the south 

 we have the remains of great volcanic activity during the Permian. 

 It was suggested that the district at its period of volcanic activity 

 may have resembled, in some ways, the San Franciscan Yolcanic 

 Field of Arizona. 



IV. — Geological Society of London. 



1. November 22, 1916.— Dr. Alfred Harker, F.R.S., President, 

 in the Chair. 



The following communication was read: — 



" Characese from the Lower Headon Beds." Bv Clement Reid, 

 F.R.S., F.L.S., F.G.S., and James Groves, F.L.S. 



The investigations here recorded have been made at Hordle Cliffs 

 (Hampshire), where the strata, below the superficial gravel, belong 

 entirely to the Lower Headon Beds, and consist of freshwater and 

 brackish-water (more or less calcareous) deposits, laid down ap- 

 parently in wide shallow lakes and lagoons. Such habitats are the 

 most favourable to the growth of Characeae, and several of the beds 

 have yielded numerous remains of these plants. 



There is a great diversity in the fruits of Chara found, representing 

 evidently a number of species, belonging to several different sections 

 or genera. With the exception of a few, which are possibly abnormal 

 variations, the fruits can be roughly grouped under the following 

 types :— 



I. Tuberculate series. (Type of C. tuberculata, Lyell = Kosmogyra, 



Stache, emend.) 



(a) Spherical. 



(b) Obovoid or pyriform, with distinctly prolonged base. 



II. Non-tuberculate series. 



(c) Large spherical, diam. c. 1 mm. (type of C. 7nedicagimcla, Brongn.). 



(d) Large ellipsoidal (type of C. helicteres, Brongn.). 



(e) Medium-sized, subglobose, tapering more or less at both ends. 

 (/) Cylindric-ellipsoidal, showing more numerous strias. 



(g) More or less pyriform : that is, definitely tapering towards the base. 

 (h) Minute, subglobose-ovoid (long. = c. 350 to 500 n). 



It is difficult to determine the exact number of species found, on 

 account of the extreme variability of some of the forms, but the 

 authors consider that at least twelve may, for the present, be con- 

 veniently treated as distinct. 



The vegetative remains are comparatively few, consisting of minute 

 portions of stems and branchlets of different diameters, and these it is 

 impossible at present to connect with any particular types of fruit. 



