242 PEOFESSOE P. M. DUPfCAN ON THE 



Paractathus humilis, sp. nov. (Plate XLIV. figs. 17-19.) 



The corallum is small, with a wide base. The costae are distinct, large, multi- 

 granular, and subequal ; inferiorly they are less separate, and the granular structure is 

 more distinct. The septa are large, and the pali also, for the size of the calice ; and the 

 primaries are very exsert and arched, the tertiaries being higher than the secondaries. 

 The pali are large and rather square, and are placed before two cycles of septa. There 

 are three cycles of septa, some of the tertiaries being absent. 



The columella is very deep and very small. 



Height of corallum -3-0 inch ; breadth of calice ^2 i°ch. 



Locality, Mediterranean Sea. 



Paeacyathus afkicanus. (Plate XLIV. figs. 20-22.) 



The corallum is conico-cylindrical, with a base more than half the breadth of the 

 calice. The calicular margin is thick, circular in outline, and the fossa is deep. The 

 columella is very small, and the papillae are distant and small. The septa are in six 

 systems ; and there are four cycles in most ; but in a few the fourth and fifth orders are 

 wanting or very slightly developed. The laminae are large, not crowded, largely 

 granular at the sides, and extend inwards not quite one third of the diameter of the 

 calice. The primaries are the largest, the most exsert, and are attached to the largest 

 costse ; and all the others project beyond the wall in continuation with the costse. The 

 secondaries greatly resemble the primaries ; and the tertiaries are smaller and less exsert 

 than the rest. Pali are placed before the septa, except those of the higher orders ; they 

 are tall, moderately stout, simple, not excised ; and those of the tertiary septa are the 

 largest, and are broader than the septal end. All are granular, and slightly bent here 

 and there. The costse are distinct to the base in some places ; but elsewhere there is 

 a dense epitheca ; where visible they are slightly spinulose externally, alternately large 

 and small, but rather subequal. Near the calice they are more prominent than 

 elsewhere. 



Height -^0 inch ; breadth of calice -j^ inch. 



Locality : Coast of Tunis, 2nd exped. ' Porcupine,' in 40 fathoms. 



Pakactathus costatus, sp. nov. (Plate XLIV. figs. 23-26.) 



The corallum is straight, cylindro-conical, with an attached base and a calice circular 

 in outline and large. The costse are distinct to the base, slightly rounded, sparsely but 

 distinctly granular, unequal ; and the highest are the primaries and those next to them. 

 The calicular margin is circular, sharp ; and the fossa is deep ; the septa are very slightly 

 exsert, and project but little into the calice ; they are thin, separate, unequal, granular, 

 and there is little difi'erence between the primaries, secondaries, and tertiaries. The 

 columella is large, slightly concave, and consists of trabeculae ending in numerous 

 papiliee. The pali are tall, not long, are distinct from the septa, stouter than these. 



