374 Beporis and Proceedings. 



■varied in diameter from six to eight feet, and were between two and 

 three feet deep, the distances between the pits being about the same 

 as the diameters. He accounted for the formation of the pits by 

 supposing that the water, which sinks into the gravel at the head of 

 the valley, flows under a stratum of clay, which prevents it from 

 rising; the water in course of time, however, flowing in very varying 

 quantities at different periods, gradually washes away small portions 

 of the clayey band, when the sand above runs through into the 

 cavity thus formed, leaving the pits described by the author. The 

 mud-volcanoes at Tarl Dab he accounted for by supposing that after 

 a fall of rain or snow the air contained in the water-bearing stratum 

 would get churned up with water and mud, and be ejected as a frothy 

 mud, sometimes to a height of three feet ; while the brine-pits in 

 the Karakash valley he believed to be formed by the excessive rise 

 and fall in the level of that river at various times, which alternately 

 fills and empties the bottoms ^of the pits, and the water left in the 

 pits gets gradually concentrated by evaporation until a strong brine 

 remains. 



Discussion. — Mr. Prestwich pointed out tkat the pits seemed due to quite 

 another cause than the pipes in the Chalk and other calcareous rocks, as they did not 

 appear to arise from erosion by carbonic acid. 



Mr. Thorp suggested an analogy between the phenomena in Yarkand and those at 

 Nantwych, and thought that the pits might be due to solution of rock-salt below the 

 surface. 



2. " On the Cervidse of the Forest-bed of Norfolk and Suffolk." 

 By W. -Boyd Dawkins, Esq., M.A., F.E.S., F.G.S. 



The author described a new form of Cervus from the Forest-bed 

 of Norfolk which he based on a series of antlers, and named G. ver- 

 ticornis. The base of the antler is set on the head very obliquely ; 

 immediately above it springs the cylindrical brow-tyne, which sud- 

 denly carves downwards and inwards; immediately above the brow- 

 tyne the beam is more or less cylindrical, becoming gradually flattened. 

 A third flattened tyne springs on the anterior side of the beam, and 

 immediately above it the broad crown terminated in two or more 

 points. No tyne is thrown off on the posterior side of the antler, 

 and the sweep is uninterrupted from the antler base to the first point 

 of the crown. The antlers differ in curvature and otherwise from 

 those of Cervus megaceros, but there is a general resemblance 

 between the two animals ; and the verticornis must have rivalled the 

 Irish Elk in size. A second species of Deer, the Cervus carnutorum, 

 which had been furnished by the strata of St. Brest near Chartres, 

 must be added to the fauna of the Forest-bed. The Cervidge of the 

 Forest-bed present a remarkable mixture of forms, such as the 

 Cervus polignacus, C. SedgwicMi, C. megaceros, C. carnutorum, C. 

 elaphus, and -C. capreolus, seeming to indicate that in classification 

 the Forest-bed belongs rather to an early stage of the Pleistocene 

 than to the Pliocene age. This inference is strongly corroborated 

 by the presence of the Mammoth, which is so characteristic of the 

 Pleistocene age. 



3. *' The Classification of the Pleistocene Strata of Britain and 



