150 



THE GEOLOGIST. 



After alluding to the single appearance of the Tenia Mulletii, confined to one 

 group consisting of two beds or zones, and to the frequent appearances of the 

 Gnjphfm; that first occur with the Perna, and range upwards through more 

 than four hundred feet of strata, ]\Ir. Norman alludes to the two groups of 

 Crioceras-zones, and to special ranges of other species, some of limited occur- 

 rence, some appearing at wide intervals, and some few of rather frequent 

 occurrence throughout many strata. All these particulars may be found in 

 Dr. Eitton's table before alluded to. 



Mr. Norman also alludes to the re-occurrence of the wealden Lo7icJwpteris 

 Mantellii in the lower greensand, found by Dr. Eitton in seven bands. At 

 "V^Hiale Chine in particular (at a distance of about five hundred feet from the 

 Atherfield beds) nodules of ferruginous sandstone, containing Panopoea, Car- 

 dium, Natica, Ammonites, &c., abound with the remains of this fern, associated 

 with twigs and branches of trees, all carbonized. Sometmies the fragments 

 and fronds are upwards of two inches long. The nodules are also scattered 

 along the shore as far as Walpen Chine, and a little beyond. Fragments of 

 coniferous wood, and remains of large cycadaceous leaves occur also in these 

 nodules. Mr. Wheeler, of Blackgang has found some good specimens ; but 

 the best that Mr. Norman has seen were collected by M. Saemann, of Paris, in 

 a block of red sand-rock, eastward of Blackgang Chine. The iguanodon has 

 also been discovered, says Mr. Norman, somewhere in the same locality ; but 

 not having been present when its discovery took place, I cannot state the 

 exact spot. Prom the character, however, of the matrix adhering to the bones, 

 I am confident as to their having been found in the upper portion of the lower 

 greensand. The teeth and portions of its skull, together with what remained 

 of its skeleton, were forwarded to the British Museum. Some other fine 

 specimens of iguanodon-bones, from the same clifi^, have been preserved at 

 Newport, and others at Hyde. 



Mr. Norman further remarks that the occurrence of fossil wood, unperforated 

 by teredo in the lower part of the lower greensa:nd, together witli fem-fronds, 

 cycadaceous leaves, and the almost complete skeletons of iguanodons, has led 

 him to think that these deposits were mainly derived from river-sediments not 

 far from an old coast-line ; whilst the worm-bored drifted wood found higher 

 Lip in the series would seem to point to a more open sea for the place of the 

 formation of the beds. 



Mr. Norman also reminds us of the re-occurrence of the wealden Clafharia 

 Lyellu in the upper greensand, and of the condition under which Pecfen quiii- 

 q/'crosffit/'s occurs four times in the Perna-beds and the " Crackers reappears 

 higluH- up, in a dimmutive state (associated with some species of Natica, Ros- 

 tcUaria, Trigonia, &c., that occurred in the " Crackers") in a hard grey gritty 

 sandstone between ClifFend and Walpen Chine; again occurs in the upper 

 greensand (at about twenty feet above the gault), in a rather diminutive form, 

 but much imju-ovcd in appearance since last met with, more tha]i tlnee hundred 

 feet below. Por tlie next fifty feet or so it occurs at intervals in the different 

 l)eds, and it gradiuvUy increases in size until it reaches the chloritic marl, where 

 (as well as in the beds of coarse chalcedony and sandstone immediately 

 below) it attams its maxinnim size of about two to three inches long, 

 and nearly as nuich in width. Here its extreme growth is attauied. In 

 the next bed, the " fossiUferous marl," it is again diminished, being no 

 more than about half an inch long. It is still smaller in the lower chalk 

 (grey chalk or chalk marl); and "as the middle chalk of the locality con- 

 tains no fossils, it is not met with until we come to the lowermost beds 

 of the ujipor white chalk, where it is associated with Spo^/r/j/li/s sjur/osns, 

 and is in a nuich more improved condition than when last seen, in the lower 

 chalk. 



