120 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 61. 



?1899. Sparsicavea undulata Gkegoey, Catalogue of Cretaceous Bryozoa in 



British Museum, p. 289, figs. 50, 51 (BibIiograpli> ). 

 1899. Sparsicavea dichotoma Gkegoey, Catalogue of Cretaceous Bryozoa in 



the British Museum, vol. 1, p. 393, vol. 2, p. 304. 

 1889. Eeteropora dichotoma Peegens, Revision des Bryozoaires du Cretace 



figures par d'Orbigny, Memoires de la Societe Beige de G§ologie de 



Paleontologie et d'Hydrologie, vol. 3. p. 373. 

 1854. MuUicrescis laxata, d'Oebigny, Paleontologie frangaise, Terrain 



Cretace, vol. 3, p. 1077, pi. 800, figs. 10. 11 (according to Pergens). 



/Structure. — The structure of this species has not been compre- 

 hended by the various authors who have studied it. The section fig- 

 ured by Hennig is incomplete and does not indicate the basal lamella. 



Fig. 35. — Grammascosoecia dichotoma Goldfuss, 1827. 



A. Longitudinal section, X 16, showing the basal (median) lamella. 



B. Tangential section, X 16. 



C. Meridian section, X 16, taken just above the basal lamella. 



D. Transverse section, X 16. 



Cretaceous (Maastrichtian) : Maastricht, Holland. 



The transverse section shows in the middle a linear structure al- 

 ways undulated, which represents the remains of the basal lamella. 

 The tubes are polygonal with adjacent walls, perceptibly equal; the 

 inequalities arise from the section which is made perpendicularly to 

 the zoarial axis and not to the tubes. 



The longitudinal section should be made perpendicularly to the 

 basal lamella, always visible on the transverse fractures. The tubes 

 are cylindrical, short, supported on the basal lamella according to the 

 method special to all short tubes; at their extremity they are re- 



