TRACHYMKDUS/E — HALICREAS. 



393 



Halicreas racovitzae. 



Homaonema racovitzx, Maas, 1906, Fauna Arctica, Bd. 4, Lfg. 3, p. 520. — Bigelow, H. B., 1909, Mem. Museum Comp. Zool. 



at Harvard College, vol. 37, p. 144. - 

 Homa-onema (Haliscera) racovitztr, Maas, 1906, Exped. Antarctique, S. Y. Belgica, Medusen, p. 10, taf. 1, fign. 3, 4; taf. 2, 



fig. 13. 



Bell nearly hemispherical, being about 8 mm. wide and 3.5 mm. high; with moderately 

 thick, gelatinous walls. 48 large tentacles, most of which were broken off short in Maas's 

 specimens, but were complete in Bigelow's and resemble those of H. papillosum; these are 

 somewhat irregularly arranged, but all ot the same size and of similar structure. There are 

 about 8 lithocyst-clubs, irregularly spaced, some octants being without them and others hav- 

 ing 2 clubs which arise from the bell-margin between the tentacles. Velum very wide, being 



Homceonema racovitza," after Maas, in Voyage S. Y. Belgica. A, side view; B, oral view. 



I mm. broad in medusae 8 mm. in diameter. 8 wide, flat radial-canals and a wide, simple 

 ring-canal. The stomach is a truncated cone with round mouth-opening; 3 mm. wide at 

 base and I mm. wide at mouth. 8 flat, shield-shaped gonads, one upon each of the 8 radial- 

 canals and extending from edge of stomach over nearly half the lengths of the canals. These 

 gonads are similar in general appearance to those of Geryonidae. The gonads are purple-violet 

 and the entoderm reddish. Bell colorless, its musculature iridescent in preserved specimens. 

 Maas found one specimen in Antarctic Ocean lat. 70° 9' S.; long. 8 2° 35' W. Bigelow 

 records two from off the coast of Peru. 



Halicreas alba. 



Haltscera alba, Vanhoffen, 1902, Wissen. Ergeb. deutsch. Tiefsee Exped., Dampfer Valdivia, Bd. 3, Lfg. 1, p. 71, taf. 9, fig. 5. 

 Homa-onetna alba, Maas, 1906, Fauna Arctica, Bd. 4, Lfg. 3, pp. 493, 520. — Bigelow, H. B., 1909, Mem. Mus. Comp. Zool. 

 at Harvard College, vol. 37, p. 142, plates 3, 33, 34. 



Bell dome-like, evenly rounded and nearly hemispherical, without an apical projection. 

 Gelatinous substance quite thick at aboral pole, but thin at margin. Bell 35 mm. wide. There 

 are 64 to 100 similar tentacles. Bigelow finds that the tentacles are similar to those of 

 H. papillosum, having a flexible, proximal part and a stiff spine-like outer end. There 

 are about 3 elongated sensory-clubs in each octant. Stomach very short and wide, and the 

 mouth is represented by Vanhoffen and Bigelow as a wide, round opening. The stomach 

 is between one-third and one-half as wide as the bell itself, and its side-walls are short and 

 conical. There are 8 wide radial-canals, each with a lancet-shaped gonad extending from 

 edge of stomach along two-thirds of length of canal. Each gonad contains 15 to 20 large, 

 spherical eggs, quite widely separated one from another. The medusa is nearly colorless, the 

 entodermal parts being sometimes more or less orange. 



A single specimen was found southwest of Cape of Good Hope, Africa, in lat. 42 18' S., 

 long. 1 4 1' E., in a vertical net dragged from a depth of 100 fathoms by the Valdivia. 



