HHIZOSTOM.E — THYSANOSTOMA, LOUIFERA. 693 



slightly and then continues throughout the greater part of its length of nearly uniform width, 

 ending in a bl unt, distal extremity, covered with frilled mouths. The wings are thin, longi- 

 tudinal lamellae, one being inward (axial) and two flaring outward (lateral). The 2 lateral 

 wings give rise each to short, small, secondary wings near their upper, outermost end. In the 

 upper third of the lower arm the frilled mouths are developed upon the outer sides as well as 

 along the edges of the 3 wings. In the middle third they are confined to the edges of the 3 

 wings; and in the lower (distal) third, they are developed upon the sides and edges as in the 

 upper third of the arm. Thus in the proximal and the distal thirds of the lower arms the 

 mouths recall the condition seen in the mouth-arms of Mastigias and Cramhione. There 

 are neither terminal knobs nor other appendages upon the mouth-arms, but there are 

 numerous short, slender, filiform, tubular appendages upon the arm-disk. 



The arm-disk is quadrangular with rounded angles, with its sides about three-eighths as 

 long as the bell-diameter. The subgenital ostia are large and gaping, 4 times as wide as the 

 perradial columns of the disk, and are not narrowed by median flaps. There is a single, large, 

 but low, subgenital porticus. 



There are only ring-muscles in the subumbrella. These are strongest near the margin 

 and the muscle-mass is widest in the 4 interradii. The muscles are only partially inter- 

 rupted in the 8 principal radii. The canal-system of the subumbrella is characterized by the 

 considerable width of the 8 rhopalar canals, which are somewhat wider than the others. The 

 ring-canal is at some distance inward from the bell-margin and the anastomozing network of 

 vessels extends on both sides of the ring-canal, fusing with the 8 radial-canals and with the 

 central stomach. 4 canals arise from the perradial sides of the cruciform stomach and extend 

 downward through the 4 pillars into the arm-disk. Here each canal divides into 4 branches, 

 2 horizontal ones leading into the center of the arm-disk and 2 vertical leading down into 2 of 

 the oral arms. Each arm-canal gives off 3 side branches which together with the axial-canal 

 extend down the mouth-arms, the side branches giving off branchlets to the 3 rows of mouths. 



This medusa is found in the Malay Archipelago, from Amboina, Philippines, and Moluc- 

 cas to Japan. It is described in detail by Haeckel, L. S. Schultze, and Kishinou\e. The 

 exumbrella is violet or mauve colored at its center, grading into russet at its margin. Sub- 

 umbrella flesh-colored. Gonads and mouth russet or hazel-brown. Mouth-arms and arm- 

 disk violet. 



Kishinouve's Thvsanostonia dcnscrispum, from Japan, is, I believe, only the \oung of 

 T. thysanura. Lesson's Rhizostoma brachyura, from New Guinea, has a whitish bell with 

 rusty-colored margin and yellowish-red mouth-frills, the general color pattern being very 

 similar to that of the more highly colored Japanese medusa. 



The dimensions in mm. of a specimen obtained at Mindanao, Philippine Islands, by 

 the U. S. Bureau of Fisheries steamer Albatross are as follows: Bell, 100 wide; perradial 

 diameter of arm-disk, 74; diameter of arm-disk at level of origin of mouth-arms, 48; genital 

 ostium, 40 wide; mouth-arms, 220 long, 24 wide at widest part, 12 wide at their blunt tips; 

 8 to 12 velar lappets in each octant; filamentary appendages on the arm-disk, 10 to 15 long; 

 exumbrella finely granular. 



In another large medusa from Mausalav, Mindoro, Philippine Islands, taken by the 

 Albatross on June 4, 1908, from a depth of 150 feet, the bell is 120 mm. wide and the mouth- 

 arms 190 long. In a half-grown medusa obtained on the surface at the same time and place 

 the bell is 59 mm. wide with fineh' granular exumbrella. Mouth-arms 67 long. Arm-disk 

 41 mm. wide at its origin from the subumbrella and t,^ mm. wide at the level of the origins 

 of the mouth-arms. 



Genus LORIFERA Haeckel, 1880. 



Himantosioma, .\gassiz, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 152. — Haeckel, 1880, Syst. der Medusen, p. 627. — Van- 

 HiiFFEN, 1888, Bibliotheca Zoologica, Bd. I, Heft. 3, p. 45. — Ma.as, 1903, Scyphomedusen der Siboga Exped., Monog. 1 1. 

 pp. 77, 81. 



Lorifera, Haeckel, 1880, IbiJ., p. 628. 



The t)pe species is L. lorifera of the Indo-Pacific region. This genus is distinguished from 

 the closely allied Thysanostoina only by the naked, club-shaped extremities of its mouth-arms. 



The name Hitnantostoriia is preoccupied, having been used by Loew, 1853, for Diptera. 

 We must therefore use Haeckel 's alternative name Lorifera. 



