LEPTOMEDUS.^ — PHIALUCIUM. 



275 



The species are all closely related and are characterized by their large, urn-shaped, 4-sided 

 stomachs and recurved lips with folded margins. 



Maas established the genus with P. virens = Oceania virens Bigelow as a type. The 

 first described species appears to be P. mbengha — Mitrocoma mbengha Agassiz and Mayer, 

 1899. The species are closely related one to another and had best be described in tabular form 

 in order to present their differences most clearly. 



Synopsis of the Species of Phialucium*. 



Shape and size of bell in mm. 



Number of well-developed 

 tentacles. 



Number of rudimentary 

 tentacle-bulbs. 



Length of largest tentacle in 

 terms of bell-radius (r). 



Number of marginal lithocysts. 



Number of concretions in each 

 lithoiyst. 



Shape and size of stomach. 



Position and character of 

 gonads. 



Color. 



Where found. 



P. carolinae= Oceania Caro- 

 lina? Mayer, 1900. 



Somewhat flatter than a hemi- 

 sphere, 14 wide. 



16 



62 



Urn-shaped, with 4 recurved 

 lips with folded lips. 

 Longer than wide. 



Linear, swollen, on outer 

 halves of the 4 radial-canals 



Entoderm of stomach, ten- 

 tacle-bulbs, and gonads, 

 bright yellow-green. 



Charleston Harbor, South 

 Carolina, and Florida, in 

 summer. 



P. mbengha Maas=Mitro- 

 coma mbengha Agassiz and 

 Mayer, 1899. 



Somewhat flatter than a hemi- 

 sphere, 9 wide. 



16 



80 ± 



Less than r. 



3 2 

 5 to 9 



Urn-shaped, wider than long. 



Linear, swollen, on outer 

 halves of the 4 radial-canals 



P. virens Maas, 1905= Oceania 

 virens Bigelow, 1904. 



Flatter than a hemisphere, 12 to 

 20 wide. 



Urn-shaped. Slightly wider than 

 long. 



Linear, swollen, on outer halves 

 of the 4 radial-canals. 



Entoderm of stomach, gonads,! Entoderm of gonads, tentacles, 



and tentacle-bulbs yellow. 

 Radial-canals grass-green. 



Suva Harbor, Fiji Islands, 

 Pacific, in January. 



and stomach light yellowish' 

 green. 



Maldive Islands, Indian Ocean 

 Malay Archipelago. 



*For Phialucium comata see text. 



Phialucium carolinae Maas. 



Plate 36, figs. 1-1". 



Oceania Carolina-, Mayer, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 7, plates 3, 4, figs. 9-1 1. 

 Phialucium caroling, Maas, 1905, Craspedoten Medusen der Siboga Exped., Monog. 10, p. 32. 



Bell not quite a hemisphere, 14 mm. in diameter. Cavity of bell shallow, so that the gelat- 

 inous substance is quite thick. 16 well-developed, marginal tentacles with large, hollow 

 basal bulbs. These are only about half as long at the bell-diameter, but as they are usually 

 carried coiled in a close helix they appear much shorter. Besides the well-developed ten- 

 tacles, there are 48 small, rudimentary tentacle-bulbs that probably never develop into ten- 

 tacles. 64 lithocysts, 4 between each adjacent pair of large tentacles. Each lithocyst contains 

 2 spherical concretions. Velum well developed. 4 narrow, straight radial-canals. Mature 

 manubrium flask-shaped, 4 simple curved lips. The gonads are developed upon the radial 

 tubes beyond their middle points. Ova in female very conspicuous. Entoderm of tentacle- 

 bulbs, manubrium, and radial tubes in region of the gonads bright yellow-green. 



This species was extremely abundant in Charleston Harbor in the early part of September, 

 1897, and in June, 1898. It is found occasionally at Tortugas, Florida. 



