154 EXPEDITION OF THE "ALBATROSS," 1899-1900. 



inwards into the substance of the velarium. The proboscis is short, and 

 there are four slightly recurved lips. There are four interradial crescentic 

 areas of numerous, short gastric cirri; the horns of each crescent pointing 

 centripetally. Four wide radial pouches extend outward from the stomach. 

 These pouches are separated one from another by four interradial partitions, 

 but are placed in communication one with another by means of the lateral 

 canals leading into the lumen of the pedalia. The gonads consist of eight 

 leaf-like folds attached to the sides of the interradial septa? and hanging free 

 in the radial pockets. The gelatinous substance of the bell is hyaline. The 

 entoderm is translucent and milky white, and the gastric cirri and flexible 

 parts of the tentacles are pink or yellow-pink. The sensory knobs of the 

 rhopalia are dull ochre in color and the ocelli are deep brown — almost 

 black. We first found a single specimen of this medusa in an open net 

 which had been towed from a depth of 300 fathoms to the surface, south 

 of Fakarava Island, Paumotus. The next day we discovered a large swarm 

 of mature individuals off Anaa Island, floating very near the surface of the 

 sea. This species is by far the largest Charybdea known. 



(300 f — S) rf ; October 14, 1899; off Fakarava Atoll, Paumotus. 

 S*; " 15, " off Anaa Island, Paumotus Islands. 



Nausithoe picta, sp. nov. 



Plate 7, fig. 33. 



The bell is quite flat and is 17 mm. in diameter. There are eight 

 solid, stiff tentacles, each of which is about as long as the bell-radius. 

 Eight marginal sense organs alternate with the tentacles. Each sense 

 organ contains a centripetal ocellus and a centrifugal otolith. There are 

 sixteen prominent marginal lappets which alternate in position with the 

 tentacles and sense organs. The mouth is situated at the centre of the 

 sub-umbrella, and is a cruciform slit surrounded by four simple, short lips. 

 Four interradial groups of gastric cirri are arranged so as to alternate 

 in position with the lips. Each of these groups contains about a dozen 

 short cirri. There are eight large gonads which lie in the tentacular radii. 

 In the female the ova are large and prominent. In the sub-umbrella there 



