ART. 13 



BJRYOZOAN FAUNA CANU AND BASSLER 



51 



DIAPEROECIA MEANDRINA. new species 

 Plate 12, Figures 5-9 



Description. — The zoarium is free, formed of bilamellar, reticulated 

 fronds, forming a meandriform ensemble with all the basal lamellae 

 oriented siiperiorily and exteriorilj^ The tubes are little distinct, 

 striated transversely; the peristomes are thin, elliptical or orbicular, 

 very little salient on the fronds, very long in the vicinity of the 

 basal lamella. The ovicell is a long, elongated sack, elliptical, very 



Figure 11.— Diaveroecia me.\ndeina, new species. A, Longitudinal section, 



X 16, TUROUGH A branch MADE IN THE ZOARIAL AXIS BUT NOT PARALLEL TO THE 

 DIRECTION OF THE TUBES. THE GEMMATION HAS THE APPEARANCE OF TRIPARIETAL 



ALONE. B, Longitudinal section, X 18, made in the direction of certain 



TUBES where the DORSAL GEMMATION IS SOMEWHAT APPARENT. C, PORTION OF 

 THE SAME SECTION, X 55, SHOWING THE MONILIFORM STRUCTURE OF THE WALL. 



D, Transverse section, X 16, exhibiting the double median lamella and 



THE TWO BERENICOID LOBES GROWING BACK TO BACK AND BECOMING FREE. THE 

 TUBES ARE CYLINDRICAL AND SEPARATED BY A CALCAREOUS TISSUE 



salient, perforated by the tubes, arranged parallel to the zoarial 

 margin. 



Structure. — The colony is a true Reticulifora so often observed in 

 the Cretaceous formations. The ovicells alone are different.^ The 

 development of the zoarium is identical with that of Diaperoecia 

 dorsalis Waters, 1879, of which we have indicated the different phases 

 in 1925.^ It is at first sight an ordinary Berenicea with two lobes 

 developing in a different plane remaining back to back and their 

 median lamella oriented superiorily and developed laterally. 



The branches are formed in an identical fashion and the basal 

 lamella, now median, is quite visible in our figure. As they are very 



* Canu and Bassler, Les Bryozoaires du Maroc et du Mauiitanie, Memoiies de la 

 National Museum, vol. 61, p. 29, pi. 5, figs. 9-12. 

 ' Idem, p. 67, pi. 9, figs. 1-16. 



