46 



The Regeneration takes place both in llie zooecia and the heterozooecia, 

 and in the former in a double manner, as an old zooecium may be replaced 

 either by a new zooecium or by a heterozooecium, and in the first case 

 there is seen a new oral margin within the old one. If an old zooecium is 

 replaced by a heterozooecium (figs. 1, 3, 4, 5) the free, distal part of the latter gets 

 another form than the corresponding part of the common heterozooecia, especially 

 when it takes up the whole of the zooecial aperture, as in that case it must of 

 course be much broader. The free part of such a heterozooecium is very much 

 protruding, and one may discern between a posterior strongly convex, from side to 

 side somewhat compressed, sometimes a little saddle-shaped surface and the frontal 

 surface which as a rule forms a right angle with the frontal area of the old zooe- 

 cium. We may compare this free part with a half somewhat compressed cone 

 which rests on the surface of (he cut and the basal surface of which wears the 

 aperture. — Sometimes the named part does not take up the whole aperture (fig. l) 

 and in that case the difference of form is not so great. When a new heterozooecium 

 is formed in an old one its free distal part, which is often vertically ascending par- 

 tially covers the corresponding part of the old heterozooecium, the tip of which is 

 seen protruding distally to it (figs. 5, 6, 7). 



The Colonies have the form of free two- or more-layered laminae. Of this spe- 

 cies I have examined or large number of fragments from Villedieu (Coniacian). 



Meliceritiles undata d'Orbigny. 



Meliceritites undata d'Orbigny, Bryoz. Crét. p. {)2,'>, pi. 737, figs. 11 — 14. 

 non .Meliceritites undata Gregory, Cret. Bryoz, p. 340, pi. XV, figs. 2 — 4, pi. XVI, fig. 3. 



(PI. IV, figs. 9-17.) 



The Zooecia, which are divided by distinct more or less prominent ridges, are 

 about twice as long as broad, and the suboral area generally presents a saddle- 

 shaped concavity in the direction proximally distally. More or less developed tu- 

 bercles. The half-elliptical aperture which is a little longer than broad lacks a 

 distinct oral ledge, but is provided with a well-developed peristomial thickening, 

 the lateral parts of which generally widen proximally, and these widened lateral 

 parts belonging to two adjacent zooecia often coalesce with the interoral tubercle 

 into a large rounded projection (fig. 17). The convex operculum is provided with 

 a flabellil'orm striation, and with very few exceptions with 1 — 4 short arched, more 

 or less distinct impressions turning the concavity proximally. When only a single 

 impression is present it is seated in the proximal part. 



The Heterozooecia which are scattered among the zooecia in rather small num- 

 ber, but not rarely two or more together, are of the same size as the latter, and 

 their obliquely ascending more or less projecting distal end is provided with an 

 aperture of somewhat dilTerent form and size, the length of which may be con- 

 tained 3 — 6 times in the length of the whole heterozooecium. It is generally narrow 



