96 



BULLETIN 11, UKITED STATES NATIONAL MUSEUM. 



irregularly polygonal, with thin walls; three to four zooecia in 2 

 mm. The lunarium is comparatively small, occupying about one- 

 fifth of the zooecial wall, but it arises from one of the angles as a 

 distinct crescent, its ends projecting into the zooecial cavity, but 

 the structure as a whole not overarching it. Mesopores few, their 

 usual number being shown in the tangential section, figure 31c. 



Excepting that the tubes are of greater diameter on account of the 

 larger zooecia, the vertical section shows the same characters noted in 

 the description of AnoloticMa rhombica. Connecting pores are pres- 

 ent but are not as numerous as in that species. The zooecial 

 waUs are of considerable thickness compared with similar species and 

 show the laminated structure clearly. In addition to the points 



Fig. 31.— Anolotichia eetalensis. a, vertical section, X9, with two layers of zocecia; &, portion 



OF THE SAME, X20, ILLUSTRATING LAMINATED WALL TISSUE; C, A NORMAL TANGENTIAL SECTION, X20. 

 OETHOCERAS LIMESTONE (B3), REVAL, ESTHONLi. 



pertaining to the zooecia, mentioned above, the occurrence of distinct 

 lunarial tubuli, varying in number from three to five, can be seen in 

 tangential sections. 



Care is necessary in separating Anolotichia revalensis from the 

 similar A. rJiombica, but it is beheved that the larger size and irregu- 

 larly polygonal shape of the zooecia in the former are sufficiently 

 different from the smaller and more distinctly rhomboidal form of the 

 latter. The other explanate ceramoporoids have a zooecial structure 

 which is not comparable to that of the present species. 



Occurrence. — Apparently uncommon in the Orthoceras limestone 

 (B3) at Reval, Esthonia. 



Gotypes.^Csit. No. 57203, U.S.N.M. 



British Museum collections, specimen and thin section. 



