222 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



its outer side the ring-canal gives rise to a fine-meshed network of 

 vessels which ramify through the lappets. 



A color note states that the medusa was light green with grayish 

 white spots. 



Genus VERSURA Haeckel, 1880. 



Crossostoma preoccupied for rnollusks by Nokbis and Lycett, 1850. 

 Crossostoma Agassiz, L., 1862, Contr. Nat. Hist. U. S., vol. 4, p. 155. 

 Versura+Crossostoma Haeckel, 1880, Syst. der Medusen, pp. 606, 607. 

 Versura Mayek, 1910, Medusae of the World, vol. 3, p. 685. 



Generic Characters. — Rhizostomata triptera with clubs and fila- 

 ments upon the mouth-arms. The 4 perradial canals arise directly 

 from the stomach, but the 4 interradial canals result from the fusion 

 of a number of anastomosing vessels which arise from the interradial 

 sides of the stomach. There is no definite ring-canal, but merely a 

 marginal network of vessels. There are no radial-muscles in the sub- 

 umbrella, but the ring-muscles are well developed. Among the char- 

 acters of minor importance, the subgenital ostia are wide openings, 

 wider than the columns between them, and the sense-organs have 

 a simple, exumbrella pit without radiating furrows. At the center 

 of the arm-disk is a prominent, raised cluster of frilled mouths hav- 

 ing filaments between them. 



VERSURA MAASI Mayer. 



Versura maasi Mayer, 1910, Medusae of the World, vol. 3, p. 687, fig. 416. 



Named in honor of Prof. Dr. Otto Maas, in recognition of his 

 notable researches upon Medusae. A single perfect specimen (Cat. 

 No. 27943, U.S.N.M. Type) was obtained by the United States Fish- 

 eries Bureau steamer Albatross on April 8, 1908, along the shore at 

 Mantacao Island, west coast of Bohol, Philippine Islands. 



Bell 90 mm. wide, flatter than a hemisphere and evenly rounded. 

 Exumbrella finely granular without furrows. Gelatinous substance 

 fairly thick but not very rigid. Eight rhopalia each with a pigment 

 spot and an exumbrella pit with smooth floor. Usually 12 marginal 

 lappets in each octant, with outer edges bluntly rounded. The 16 

 rhopalar lappets are slightly narrower than the velar lappets. Arm 

 disks five-ninths as wide as bell-diameter at the level of the origin of 

 the eight mouth-arms. The four interradial subgenital ostia are two 

 times as wide as the perradial columns of the arm-disk. Eight mouth- 

 arms each one-third as wide as the bell-diameter. The three- winged 

 lower part of each arm is somewhat more than two times as long as 

 the unbranched upper part of the arm. The two lateral outer wings 

 of each arm are deeply cleft. (See fig. 21, C.) There are a large 

 number of laterally flattened clubs at the center of the arm-disk. 

 These are besprinkled with small nettle-warts which are most promi- 

 nent at the broad outer end of the club. In addition there are a few 



