On the Monticiiliporoids of the Citiciiuiiti Group. 159 



Monotrypella, Ulrich, Jour Cin. Soc. Nat. Hist., V., p. 153, 

 1882. 



Afuplexopora^ Ulrich, Ibid, V., p. 154, 1882. 

 Batostoma, Ulrich, Ibid, V., p. 154, 1882. . , 



Batostomella, Ulrich, Ibid, V., p. 154, 1882. 

 Aspidopora, Ulrich, Ibid, V., p. 155, 1882. 

 Pdigopom, Ulrich, Ibid, V., p. 155, 1882. 

 Discotrypa, Ulrich, Ibid, V., p. 155, 1882. 

 Spatiopora.^ Ulrich, Ibid, V., p. 155, 1882. 

 Cheiloporclla, Ulrich, Ibid, V., p. 157, 1882. 

 Ceramopordla, Ulrich, Ibid, V., p. 156, 1882. 

 Hoiiiotrypa, Ulrich, Ibid, V., p. 240, 1882. 

 Lcptotrypa, Ulrich, Ibid, VI , p. 158, 1883. • • 

 Atactoporclla, Ulrich, Ibid, VI., p. 247, 1883. 



Corallum variable in shape, massive, ramose, laminar, frondes- 

 cent, encrusting, or assuming a certain peculiar form ; attached or 

 floating free. Composed of numerous tubular corallites, the walls 

 not amalgamated with each other, and mostly without pores, but 

 these present in a few rare instances. Tubes mostly of two kinds, 

 one (interstitial) smaller than the other, and differing in internal 

 features. Interior of the tubes with few or many complete tabulae, 

 or diaphragms, or more or less vesicular, (in sub genus Fistuli- 

 pora). The interstitial cells more closely tabulate than the larger ones, 

 sometimes so numerous as to completely isolate the large tubes 

 from one another (in sub-genus Fistulipora). The apertures of 

 the cells generally straight, sometimes more or less oblique, varying 

 in shape from circular, oval, hexagonal or polygonal, to square or 

 rhombic. Surface often showing at intervals areas occupied by 

 corallites larger or smaller than the average. If elevated above 

 the surface known as "monticules," and if on, or below it, as 

 "maculae." Sometimes forming, (in sub-genus Constellaria), 

 star-shaped elevations, more or less thickly scattered over the sur- 

 face. Spiniform corallites more or less numerous, placed either at 

 the angles, on the edges of the cells, or, at times, projecting into 

 the cell cavity; sometimes, (in sub-genus Dekayia), projecting 

 above the surface as conspicuous blunt spines. 



It will be noticed that in the above description of the genus 

 there is no mention of any internal features save one, the tabulse in 

 the tubes. These features have purposely been left out because we 



