31 



The Colonies are incomposite, and the cylindrical fragments examined contain 

 c. 10 zooecia in each transverse series. 



I have examined a rather scarce number of fragments from Rügen and from 

 Möen, and while in the specimen from Rügen the aperture is only as long as the 

 suboral area in those from Möen it is more than half a time longer. 



Melicerititis gothica, var. acuminata n. 



(PI. II, figs. 23—24.) 



The Zooecia are hexagonal, and the aperture which is not far from being double 

 as long as broad has the form of an elongate triangle the lateral margins of which 

 are somewhat convex in their proximal part and a little incurved in their distal 

 half. The distal part of the oral ledge is strongly developed, and may sometimes 

 be all most half as long as the whole aperture. All other features as in the main 

 form. 



Very common in the chalk (upper Senonian) from Tullstorp (Sweden) and from 

 Svinkloven (Jutland). 



Meliceritites pentagonuin n. sp. 



(PI. IV, fig. 22.) 



The Zooecia which are divided from each other by well-developed marginal 

 ridges are more or less distinctly hexagonal, and in most cases about half a time 

 as long as broad. As a rule distinct tubercles. The large aperture which does 

 not take up the whole breadth of the zooecium in its distal part is more or less 

 distinctly pentagonal, the two distal sides of the pentagone being sometimes repre- 

 sented by a curve while the two proximal paired sides are always distinctly con- 

 verging proximally. It is provided with a well-developed oral ledge the two halves 

 of which form with each other an acute or sometimes right angle. The oral ledge 

 which is very narrow within the two paired proximal sides does not as in other 

 species attain its largest height in the middle line, but in the two lateral halves. 

 There is a well-developed peristomial thickening, the distal strongly projecting part 

 of which belongs to the marginal ridges, and this part together with the supra- 

 oral tubercle often forms a more or less prominent beak-like projection. All the 

 hitherto examined specimens have lost their opercula. 



The Heterozooecia, which are spread among the zooecia in groups of 2 — 9 are 

 of somewhat variable size, the smallest of them, however, not being much smaller 

 than the zooecia. They are provided with a long narrow proximally gradually 

 widening aperture, the narrow opening of which is bordered by two lateral pro- 

 cesses. The aperture is of very different length and in the largest of them it is 

 longer than the concave suboral area and takes up the whole breadth of the hetero- 

 zooecium in its distal third part. 



