1883.] 



MADREPORARIAN GENUS PHYMASTR/EA. 



409 



V. Dpscription of a new Species. 



PhYMASTR^A irregularis, SJ). iiov. 



The corallum has a small adherent base and a large irregularly 

 hemispherical shape, the surface being gibbose here aud there. The 



Fig. 1. 



Phymasfrma irregularis (coralhmi fiom above). 



Fig. 2. 



Phyma&trmi irregularis (side view of ;i eorallite). 



coralhtes are numerous, are small at the base, widen rapidly with 

 height, and are very irregular in their outlines and dimensions'; each 

 is separated from its neighbours even at the calice by a narrow space 

 which is crossed by slender junction-processes. The calices vary in 

 size and shape and are ratiier deep ; they are angular in outline 



