Contributions to Invertebrate Palaeontology. 579 



The rays are very fine and slender, with slightly elongated, quad- 

 rangular fenestrules. The rays are finely striate longitudinall}^, but 

 too imperfect for use or identification. 



Synocladia rectistyla. 



Plate XIII, figs. 9 and 10. 



Synocladia rectistyla Whitf., Ann. N. Y. Acad. Sci., 1882, p. 220. 



Brjozoum growing in spreading funnel-formed fronds, rising from a rooted 

 base and widely diverging in their upward growth ; the inner surface of the 

 cup bearing pores. Rays straight and somewhat rigid in their upward direc- 

 tion, with frequent bifurcations, which are not abrupt with rapidly diverging 

 branches, but rise gradually from a thickened space, and gradually diverge as 

 slender but constantly thickened rays until the normal strength is attained. 



The rays are slender, rather closely arranged ; about six of them occupying 

 the space of a fourth of an inch in the widest parts, and from eleven to twelve 

 may be counted in the same space in the most crowded parts. 



Transverse dissepiments nearly as strong as the longitudinal rays, and often 

 slightly arched upwards between them in the wider parts, but more frequently 

 directed obliquely upward in passing from one ray to the next, and very often 

 directed upward to the right from one side of a ray, and to the left on the 

 opposite side ; but they are generally direct in the more crowded portions. 

 The middle of the ray on the poriferous surface is elevated or roof-like, with 

 a central crest or ridge bearing distant nodes ; a single row of large pores is 

 arranged on each side, which are usually less than their own diameter apart, 

 and more or less alternating with those of the opposite side. From two to 

 three pores occupy each side of each fenestrule, and the pores are margined 

 by an elevated lip, which on unworn spaces are very prominent. From one 

 to three similar pores, although sometimes of smaller size, occupy the surface 

 of each dissepiment. Non-poriferous surface not observed. 



This species is somewhat similar to »S'. biserialis Swallow (Trans. 

 St. Louis Acad. Sci., vol. i, p. 119), as identified and figured by Mr. 

 F. B. Meek (Final Kept, of U. S. Geol. Surv. Neb., pi. 7, fig. 5), 

 but differs in wanting the longitudinal nodose ridge between the 

 pores of the dissepiments, and in having only a single row of pores 

 on those parts occupying the middle of the dissepiment as well as 

 in the more slender, finer, and more direct, and much more crowded 

 rays, also in having a larger number of somewhat smaller pores 

 on the rays. Mr. Meek, loc. cit., identifies the above species with 

 Synocladia Cestriensis {Septipora Cestriensis Prout, Trans. St. 

 Louis Acad. Sci., vol. i, p. 448, pi. 18, fig. 2), which differs from the 

 Ohio specimens in the stronger and thicker, as well as more flexuose 

 rays ; in the rounded fenestrules, and smaller-sized pores, which are 



