REPORT ON THE DEEP-SEA MEDUSAE. 89 



the preceding species. The unusual strength of this large proboscis indicates a predatory 

 mode of life. 



The central stomach appears capable of being completely shut off from the buccal 

 stomach, as the palatine opening {gp) is narrowed by strongly-projecting palatine 

 swellings, and both the four perradial palatine nodes (gk) and the contiguous lateral parts 

 of the palatine grooves are also considerably thickened. On the other hand, the four 

 obelisk plates of the central stomach are very delicate and thin walled (torn for the most 

 part). The four perradial angles of the quadrate pyloric opening coincide with the 

 four proximal ends of the four cleft-shaped gastral openings. 



The basal stomach (gb) shows an essentially different formation from that of the pre- 

 ceding species. In the latter the four perradial peripheric niches surrounding its 

 conical axial space are completely separate from each other, whilst the four interradial 

 funnel cavities of the subumbrella run above as far as the point of the conical basal 

 stomach and meet there in the centre of the umbrella cone. In Periphema regina, on 

 the other hand, the interradial funnel cavities end 2 cm. below the basal centre point of 

 the basal stomach. The latter consequently forms a quadratic undivided depression in 

 the bottom of the flatter vaulting of the cone with the funnel cavities and their phacelli 

 springing from its four angles. The distance of these four points (the lateral length of 

 the quadrant) amounts to 4 cm. The shattered condition of the fragments before me, 

 did not allow of the complete reconstruction of the basal stomach. The central part of 

 the umbrella cone with its four funnel points was, however, preserved, and showed clearly 

 that the four perradial niches of the basal stomach communicate freely. This 

 peculiarity distinguishes Periphema generically from Periphylla. 



The phacelli or longitudinal rows of gastral filaments in Periphema regina are 

 extremely large and more strongly developed than in any other Medusa known to me. 

 They consist of several thousand strong and very long filaments, placed in several rows 

 along the gastral tseniola (not in a single row as in the preceding species). The filaments 

 are longest in the middle of the phacelli, up to 80 mm. long and 1 mm. thick. They 

 become shorter and thinner towards both ends, and are then mostly only 10-20 mm. long 

 and hardly 0"5-0 - 2 mm. thick. Their special formation and distribution is the same as 

 in the previous species. Two diverging phacelli run from the cone point of each of the 

 four interradial funnels, extending on the lateral margins of the gastral openings as far 

 as the pylorus, and ending 1 cm. above the palatine groove (fig. 1). The filaments are 

 sometimes cylindrical, sometimes flattened like a ribbon, often thickened into knots and 

 tongue-shaped at the end. The nature and disposition of these glands is the same as in 

 the preceding species. The lumen both of the central and the basal stomach is occupied 

 for the most part by this mass of filaments. 



The peripheric coronal intestine in Periphema regina shows the same formation as 

 that already described in detad in Periphylla mirabilis (p. 78). The colossal coronal 



(ZOOL. CHALL. EXP. PART XII. 1881.) M 12 



