100 COELENTERATA—ANTHOZOA SUB-BRANCH II 
Striatopora, Hall (Fig. 176). Like the preceding, but with tubes contracted 
by stereoplasma at a greater depth, so as to give the calices a funnel-shaped 
appearance. Silurian and Devonian. 
Alveolites, Lam. (Fig. 177). Corallum massive or branching, composed of 
small, contiguous, compressed, thin-walled corallites, with obliquely opening 
triangular or semilunar calices. Septa very faint, represented merely by ridges 

Hig. 107. Pleurodictyum problematicum, 
A, Alveolites suborbicularis, Lam. Middle Devonian; Gerolstein, Hifel. Goldf. Lower Devonian; 
Natural size. B and C, Alveolites Labechei, E. and H. Silurian (Wenlock) ; Coblenz. Natural size. Vermi- 
Tronbridge, England. Tangential and vertical sections, 10/; (after Nicholson). form foreign body in the centre. 
or rows of spinules, sometimes but a single row present. Mural pores of large 
size, irregularly distributed. Very common in Silurian and Devonian. 
Cladopora, Hall. Coenites, Kichw. Silurian and Devonian. 
Pleurodictyum, Goldt. (Fig. 178). Corallum depressed, discoidal, circular, 
or elliptical in contour, lower surface covered with concentrically striated 
A B c 

Fic. 179. 
Michelinia fauvosa, de Kon. Carboniferous Limestone; Tournay, Belgium. A, Coralluin from above. 
B, Lower surface with radiciform epithecal processes. C, Vertical section (after Gaudry). 
epitheca, and frequently with foreign vermiform body occupying centre of the 
base. Corallites small, polygonal, contracted inferiorly so as to become funnel- 
shaped. Septa represented by faint marginal ridges, or obsolete. Walls 
pierced by irregularly distributed mural pores. Tabulae scanty. Devonian. 
P. problematicum, Goldfuss, is tolerably abundant in the Lower Devonian 
“Spirifera sandstone” of the Eifel, but is only known in the form of casts. 
