406 Lindstrom— On Zoantharia Ragosa. 



the brick-earth, of Hoxne may, so far as their position affords a clue, 

 be of any age subsequent to the Boulder-clay ; but those described 

 by Mr. Prestwich, near Eeculver, containing Cyrena Jluminalis, as well 

 as those of Sangatte, near Calais, would, both by their position and 

 organic contents, seem to fall into the series x5 ; while those at 

 Wissant, described by Mr. Day at page 115 of the 3rd volume of this 

 Magazine, would seem to come nearer to the series a; 6 than any 

 other. " The clay with flints " and " brick-earth " of the Ordnance 

 Surveyors, which occupies a belt of the Chalk country, stretching 

 from near Marlborough to High Wycombe, seems by -position to 

 come nearest to the group x5. 



IV. — Some Observations on the Zoantharia Eugosa. 



By GUSTAVE LiNDSTKOM, Ph.M. 



[^Continued from the August Number, p. 361.] 

 [PLATE XIV.i] 



THE next operculated species which claims our attention is the 

 Galceola Gotlandica of F. Eoemer. This species has been re- 

 moved from the class BracMopoda in a list of the Upper Silurian 

 Brachiopods which I published in 1860. I now give juj reasons for 

 so doing (then but briefly indicated). 



The shell presents on its exterior two different surfaces, one 

 almost flat and triangular, the other convex (Plate XIV. Tigs. 8-11, 

 etc. ) The shell has thus the shape of an irregular semi-cone. 

 Close and irregular lines of growth continue interruptedly across 

 these surfaces, and give the flat one, especially, a wrinkled appear- 

 ance. Eectangular to these lines, or parallel to the longitudinal axis 

 of the shell, are seen extremely delicate and dense stria3. The flat 

 surface is divided in the middle by a longitudinal ridge, which is 

 formed by two or three larger striae, and by a regidar folding out- 

 wards of the rim of the calyx. At the rounded angle, where the 

 two different surfaces meet, rootlike processes project, just as in 

 Goniophyllum. They often occur in pairs, in some instances on the 

 flat surface, in others (Plate XIV. Fig. 12 and 13) on the convex side. 

 By means of these rootlets they fixed themselves in their young 

 state to Halycites, Favnsites, and other marine bodies. The rootlets 

 are perforated by a very narrow channel, which opens within the 

 calyx. Of all the Cyatlwphyllince provided with rootlets none so 

 clearly shows the connection between the channel of the rootlet and 

 the cavity of the calyx as this species. The membrane which lined 

 and secreted the walls of the calyx then formed small branches, 

 which also secreted calcareous matter around themselves and thus 

 formed these rootlike tubes. Their function of attaching the shell 

 ceased when this became of too great a size, they then curve back- 

 wards along the flat surface, and terminate on it without opening ; 

 consequently, they continued to be formed long after their original 



1 For Plate XIV. see Geol. Mag., August, Vol. III., p. 356. 



