ART. 22. CYCLOSTOMATOUS BRYOZOA — CANU AND BASSLER. 29 



PLAGIOECIA OBLIQUA D'Orbigny. 1851. 



Plate 5, tigs. 9-32. 



1851. ReticuUpora obliqua d'Oebigny, Palgontologie francaise, Terrain 

 Craac6. vol. 5. p. 906, pi. 610, figs. 1-5; pi. 768, figs. 1, 2. 



1899. Crisirw (Reticrisina) obliqua Gregory. Catalogue of the Cretaceous 

 Bryozoa, p. 178, pi. 8, figs. 8, 9, and fig. 13 (cites bibliography and 

 geological distribution). 



Structure. — ReticuUpora is a very curious zoarial form, lon<5 con- 

 sidered as generic ; it results from a folding of a primitively Bereni- 

 coid zoarium and of the turning toward the top of the folded fronds. 

 The ovicells observed indicate that this zoarial form may be produced 

 in very different families. 



Here the ovicell is elliptical or fusiform, quite long, transverse, 

 arranged parallel to the zoarial margins, and obliquely to the tubes. 

 It is located among the tubes, the development of which it retards, 

 but it may be placed on the margin itself of the zoarium. We give 

 some illustration.s which show its variations in size, form, and posi- 

 tion. 



This species is common in the European Cretaceous and specimens 

 with ovicells are not rare. In the American Tertiary (Vicksbur- 

 gian) we have a species with a ReticuUpora zoarium belonging to 

 EoBochoecia a genus of the Mecynoeciidae. 



Occurrence. — Cretaceous (Coniacian) : Tours (Indre-et-Loire), 

 France. 



NOTOPLAGIOECIA, new genus. 



Greek: Notos, back, dorsal. 



The ovicell is an irregular convex capsule replacing many peris- 

 tomes. The tubes are short, clubshaped with thick moniliform walls 

 at their extremities. The gemmation is dorsal. There is no basal 

 lamella. 



Provisional genotype. — N otoplagioecia far ring donensis, new species. 



Range. — Cretaceous (Aptian-Coniacean) . 



In the genus Plagioecia Canu, 1917, there are species provided with 

 a basal lamella and others that are deprived of it. The first group 

 has triparietal gemmation while the second has dorsal gemmation. 

 It is convenient to regard the second group as a distinct genus. In 

 this new genus, N otoplagioecia., it is necessary to classify the follow- 

 ing species in addition to the new species here described. Laterotubi- 

 gera -fiexuof^a D'Orbigny, 1853, and L. annulata D'Orbigny, 1853. 



Many other species of the genus Later otuhigei^a D'Orbigny, 1853, 

 appear to belong to this new genus. Perhaps it will ultimately be 

 found that D'Orbigny's genus Later otuhig era, possesses the same 

 characters of ovicell and gemmation, but at present this genus can not 

 be recognized. 



