AKT. 22, CYCLOSTOMATOUS BKYOZOA CANU AND BASSLER. 17 



In 1898, Canu gave the principal variations of the ovicell, which 

 is sacciform (fig. 3), cordiform (fig. 4), or pyriform (fig. 5). Un- 

 fortunately his figures only represent specimens with peristomes ar- 

 ranged in quincunx. In 1914 Waters, in verifying the species, wrote : 

 " Canu does not figure the spiral zooecia or regular, therefore, why 

 does he call it Spiropora'^''? and he made the generic correction 

 indicated in our bibliography. 



In reality this species affects the two forms, Entdlophora and 

 Spiropora^ and the two arrangements of the peristomes are often 

 visible on the same specimens (fig, 7), There is, therefore, no error 

 in the determination. The identity of the ovicell of a branch with 

 verticells (fig. 6) with that of a branch without verticells (fig. 5) is 

 another very convincing proof. The most extraordinary variations 

 affect also the diameter of the peristome, which varies fi-om 0,14 (fig. 

 8) to 0.20 (fig. 9). Thus detailed study of this species confirms the 

 perfect uselessness of the two supposed genera Entcdophora and 

 Spiropora^ based on the arrangement of the peristomes. 



Occurrence. — Jurassic (Bathonian) ; Occaignes (Ome), France. 



Plesiotype.— Cat No, 68910, U.S.N.M. 



MECYNOECIA VARIABILIS Hagenow, 1861. 



Plate 2, fig. 14. 



1851. Pustulopora vnriaMlis HAGENo\y, Die Bryozoen der Maastrichter 

 Kreidebildung, p. 19, pi. 1, fig. 9. 



We have found a fragment of this species bearing an ovicell which 

 shows that, without doubt, it is a Mecynoecia. Our photograph is 

 quite similar to Hagenow's figure, and we do not understand how 

 Gregory, in 1899, could class the species in Clausa. The section, 

 which he illustrates, must certainly have been made from a badly 

 determined specimen. Pergens, in 1888, classed the species with 

 certainty in Entdlophora. 



Occun'cnce. — Cretaceous (Maastfichtian) : Maastricht, Holland. 



Plesiotype.—Q2it. No. 68910, U.S.NM. 



TRIGONOECIA, new genus. 



The ovicell is pyriform, symmetrical, convex, wrinkled transversely. 

 The oeciostome is small, salient, terminal, median, on the same plane 

 as the ordinary peristomes. The tubes are cylindrical, with triparie- 

 tal gemmation on a basal lamella. 



Genotype. — Trigonoecia (Mesenferipora) viichelini Blainville, 

 1830. 



Range. — Jurassic (Bajocian-Albian) . 



