276 MEDUSAE OF THE WORLD. 



Phialucium virens Maas. 



Oceania virens, Bigelow, 1904, Bull. Mus. Comp. Zool. at Harvard College, vol. 39, p. 252, plate I, figs. 3, 4. 

 Phialucium virens, Maas, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 32, taf. 4, fign. 36, 37; 1906, Kevue 

 Suisse de Zool., tome 14, p. 93. 



Bell flat, shield-shaped, lenticular, with thin but firm gelatinous substance; 12 to 20 mm. 

 wide, 4 to 7 mm. high; 16 to 20 short tentacles, irregularly arranged, tapering, and about 

 half" as long as the bell is high. Besides the tentacles there are 30 to 80 rudimentary tentacular 

 knobs upon the bell-margin, irregularly scattered between the tentacles. 32 lithocysts, each 

 with one or two spherical concretions; the lithocysts are somewhat irregularly scattered, 

 there being usually 2 or 3 between each pair of tentacles. Manubrium short, flask-shaped, 

 very distensible, 4 pointed lips. 4 large gonads on distal halves of the 4 radial-canals. 



Bell colorless. "Gonads, manubrium, and tentacles light yellowish-green. 



MaldiveIslands,IndianOcean; December and January. Malay Archipelago. Ouiterare. 



This form is probably identical with P. mbengha of the Fiji Islands, but its lithocysts 

 appear to contain only I or 2 concretions instead of 5 to 9 as in P. mbengha. 



Phialucium comata Bigelow. 

 Phialucium comata, Bigelow, H. B., 1909, Mem. Mus. Comp. Zool. at Harvard College, vol. 39, p. 158, plates 5, 6, and 37. 



Bell somewhat higher than a hemisphere, 6 to 12 mm. in diameter. Gelatinous sub- 

 stance thick, bell-cavity deep. In Pacific medusae there are about 17 tentacles and 23 



rudimentary knobs on the bell-margin, but in the 

 West Indian variety, when 12 mm. wide, there 

 are 19 tentacles and 62 knobs, and at all stages 

 there are more knobs in the West Indian medusa?. 

 The tentacles are short, with swollen basal bulbs 

 flanked by 1 to 3 pairs of lateral cirri. Cirri also 

 flank the larger knobs. There are 7 to 14 large 

 closed lithocysts. Number of concretions ( ?) 

 Manubrium short, flask-shaped with a low 

 peduncle and 4 slightly crenulated lips. Gonads 



Fig. i^.-Phialucium virens, after Bigelow, in Bull. l| near f rom tne middle third to near the Outer 



Museum Comp. Zool. at Harvard College. . . . 01 „„.„• U 



ends ot the 4 radial-canals. (jonads greenish, 

 other parts colorless. Found in Acapulco Harbor, Pacific coast of Mexico, and at Guade- 

 loupe, West Indies. Distinguished by its lateral cirri and few but large lithocysts. It falls 

 within Torrey's new genus, Phiahpsis, and may more properly be called Plualopsis comata. 

 (See appendix.) 



Phialucium mbengha Maas. 

 Mitrocoma mbengha, Agass.z, A., and Mayer, 1899, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, p. 168, plate 8, figs. 24, 25. 

 Phialucium mbengha, Maas, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 32. 



For description see synoptic table of Phialucium. 



Genus BLACKFORDIA, gen. nov. 



This genus is named in honor of my friend, the late Eugene G. Blackford, who, as Fish 

 Commissioner of the State of New York, was a pioneer in the solution of important problems 

 in the commercial culture and propagation of food-fishes; and whose active interest in behalf 

 of the institution of the New York Aquarium entitles him to be remembered as a founder ot 

 that beneficent educational establishment. 



GENERIC CHARACTERS. 



Eucopida? with numerous closed, vesicular lithocysts upon the bell-margin between the 

 tentacles. The entodermal cores of some or all of the tentacles extend inward from the hell- 

 margin into the gelatinous substance of the bell. The manubrium lacks a peduncle. No 

 marginal cirri. No permanently rudimentary tentacles. Hydroid unknown. 



This genus is distinguished from Obelia by the numerous (more than 8) lithocysts upon 

 the bell-margin. In general appearance the medusae remind one of A. Agassiz's figure of 



