MARYLAND GEOLOGICAL SURVEY 437 



Occurrence. — St. Mary's Formation. St. Mary's Kiver, Cove Point. 

 Calvert Formation. Plum Point. 



Collections. — U. S. National Mviseiun, Maryland Geological Survey. 



MiLLEASTER ( ?) SUBRAMOSUS n. Sp. 



Plate CXXI, Figs. 11a, lib. 



Description. — Polypariuni attached apparently loosely to foreign 

 bodies and consisting of several short branches or mere lobes springing 

 from a slightly expanded base. Zooidal pores of the larger size almost 

 confined to the growing extremities of tlie brandies and lobes, their sides 

 and the expanded base being occupied chiefly by coenenchymal tissue the 

 surface of which exhibits, liesides numerous granules or spines, numer- 

 ous small pores and is traversed by strong astrorhizal grooves. The 

 stellate pores have only moderately elevated margins and, on the ends of 

 the branches, these are in conlact. Within their apertures the septa are 

 nearly as well developed as in M. incrustans. The larger of the two sets 

 of non-septate pores occurring in the spans between the septate pores in 

 that species has not been certainly observed, but the smaller set is abun- 

 dantly represented. 



Vertical fractures of the basal expansion exhibit interlaminar cham- 

 bers and small vertical tuliuli very much like those occurring in Hydrac- 

 tinia muUispinosa and shown in fig. 8 on Plate CXXI. Where one of the 

 branches has been broken away the fracture shows, besides the tubulate 

 interspaces, only transverse sections of septate pores looking much as 

 they do at the surface. There is some evidence of tabulae, but it is not 

 conclusive. 



In placing this species of Milleaster I rely principally upon the pres- 

 ence of a set of septate pores. Excepting that there are no large spines, 

 the basal part of the polyparium is very much as in Hydractinia, but the 

 septate pores on the ends of tlie branches have no parallel in that genus. 

 These same septate pores forbid placing the species under Millepora, 

 which is suggested by the generality of the other characters. Unfor- 

 tunately the material at hand is too scanty to permit working out all the 

 details of structure and until more is found the above provisional 

 arrangement mvist suffice. 



