98 



BULLETIN 11, UNITED STATES NATIONAL MUSEUM. 



excrescences. Zocecia large, with moderately thin walls, dnect, hexagonal or sub- 

 rhomboidal apertures. The latter are subequal (there being no distinguishable 

 clusters of large ones) , are arranged in rather regular series with 11 in 5 mm . Lunarium 

 well developed, appearing as a small crescentic elevation usually in one of the angles. 

 Mesopores few, sometimes appearing to be absent entirely, occasionally forming small 

 clusters of from two to six. 



Internal characters. — In tangential sections the walls of contiguous zocecia appear to 

 be thoroughly amalgamated, the lunarium is represented by two or three small lucid 

 spots (lunarial tubuli) on one side of the tube, the end ones projecting slightly into 

 its cavity. In vertical sections the tubes are scarcely to be called vertical even 



in the axial region, ciu-v- 

 c ing outward with a uni- 



form curve from the be- 

 ginning. Their walls are 

 composed of rapidly alter- 

 nating dark and lighter 

 shades of schlerenchyma, 

 so that they appear more 

 or less distinctly lineate 

 transversely. The cause 

 of these lines, which are 

 closest in the peripheral 

 part of the zoarium, is 

 unknown, unless the light 

 ones, which are of uni- 

 form width and, espe- 

 cially in the axial region, 

 narrower than the dark 

 bands, represent rows of 

 perforations . Exceed- 

 ingly delicate dia- 

 phragms, their diameter 

 or more apart, occur 

 chiefly in the outer and middle part of the tubes. The axial portion of transverse 

 sections is very nearly like tangential, the only difference being that the walls are 

 a little thinner and small tubes comparatively more abundant. 



Occurrence. — ^Very abundant in the Stictoporella bed of the Black 

 River (Decorah) shale at various localities in Minnesota and Iowa. 

 Rather uncommon in the Kuckers shale (C2), Baron Toll's estate, 

 near Jewe, Esthonia. 

 ' Plesiotype.— Cat. No. 57204, U.S.N.M. 



One specimen from Baron Toll's estate is in the collection of the 

 British Museum. 



ANOLOTICHIA SACCULUS, new species. 

 Text fig. 34. 



Zoarium a small, sack-Hke body, narrow at the lower end, broad in 

 the upper portion. The two type-specimens are of about equal size, 

 but the more perfect one, shown in figure 34 a, is about 15 mm. high and 

 12 mm. at its greatest width. The zooecial layer forming this hollow 

 body is less than a millimeter in thickness, with the zooecial apertures 



Fig. 33.— ANOLOTICHIA impolita. a, fragment of zoarium, natural 

 size; 6 AND c, tangential and vertical sections, X18, introduced 

 for comparison with figure 32. kuckers shale (02), baron 

 Toll's estate, Esthonia. 



