218 MEDUSAE OF THE WORLD. 



ininate in a knob-like cluster of nematocysts. Some of the medusae lack cirri and Bigelow 

 never saw more than 3 upon a single medusa. The cordyli or clubs upon the bell- 

 margin are more numerous than the tentacles. There are no lithocysts and no ocelli. 

 When young the outlines of the 4 broad radial-canals are plain. Later they develop short, 

 simple, lateral diverticula and then the gonads develop in the interspaces of these branches 

 close to the subumbrella as in P. longigona. The manubrium is quadrate basally and its 

 side walls are short and barrel-shaped with a widely open mouth. 



Basal parts of radial-canals, manubrium, and tentacle bulbs are brilliant opaque brick- 

 red; gonads and outer parts of canal system and tentacles lighter. A pale colored line 

 extends along the central line of each radial-canal forming a cross at the middle of the 

 stomach. The entoderm cells contain red, yellow, and black granules, and the ectoderm 

 cells minute, red granules. 



This medusa is one of the intermediate fauna found at depths of about 300 fathoms 

 in the Humboldt Current off the coast of Peru. Torrey describes another species of 

 Ptychogena from the California coast. (See appendix.) 



Genus POLYORCHIS A. Agassiz, 1862. 



Polyorchis, A. AGASSIZ in L. Agassiz's, 1861, Cent. Nat. Hist. U. S., vol. 4, p. 349; 1865, North Amer. Acal., p. 1 19. HAECKEL, 

 1879, Syst. der Medus.n, p. 149. MURBACH AND SHEARER, 1903, Proc. Zool. Soc. London, vol. 2, p. 174. 



The type species is Polyorchis penicillata A. Agassiz, from the Pacific coast of the United 

 States. 



GENERIC CHARACTERS. 



Thaumantiadae with 4 radial-canals which give rise throughout their lengths to many 

 blindly ending side branches. Marginal ring-canal simple and bell-margin not divided into 

 lobes. Numerous sac-like, sausage-shaped gonads attached to the radial-canals and their side 

 branches. Stomach long, tubular, and with 4 simple lips. 



Polyorchis penicillata A. Agassiz. 



( ?) Medusa campanulata, DE CHAMISSO ET EVSENHARDT, 1820, Nova Acta Phys. Med. Leop. Car., tome I o, p. 359, plate 30, fig. I. 



Meliccrtum pcniciltatum, ESCHSCHOLTZ, 1829, Syst. der Acalephen, p. 106, taf. 8, fig. 4. 



Aglaura penicillata, DE BLAINVILLE, 1834, Man. d'Actinologie, p. 283, plate 33, fig. 4. 



Polyorchis peniciUata, A. AGASSIZ in L. Agassiz's, 1862, Cont. Nat. Hist. U. S., vol. 4, p. 349. AGASSIZ, A., 1865, North Amer. 

 Acal., p. 119, figs. 179-183. FEWKES, 1889, Amer. Naturalist, vol. 23, p. 593, figs. 3,4; 1889, Bull. Essex Inst. Salem, 

 vol. 21, No. 7, p. 103, plate 4, figs. 6, 7. BANCROFT, 1904, Journ. Exper. Zool., Baltimore, vol. i, p. 289, 4 figs, (reac- 

 tions to galvanic currents). BANCROFT, 1906, University of California Publications, Physio]., vol. 2, p. 43, 4 figs. 



Polyorchis pinnatus+P. penicillatus, HAECKEL, 1879, Syst. der Medusen, pp. 149, 150, taf. 8, fig. 13. 



Polyorchis , LOEB, 1906, Journ. Biological Chemistry, New York, vol. I, No. 6, p. 427 (physiological), 



Polyorchh campanulata -+- P. penicillata, BEDOT, 1905, Revue Suisse de Zool., vol. 13, pp. 143, 144 (citation of all papers to l8<;o). 



Polyorchis , LOEB, 1906, Dynamics of Living Matter, Columbia Univ. Biol. Series, No. 8, pp. 87, 91, 141. 



Polyorchis , MACCALLUM, 1907, The Journal of Biol. Chemistry, vol. 2, No. 4, p. 385, New York. 



Bell about 50 to 60 mm. high, 30 to 40 mm. wide, with a slight, solid, apical projection and 

 almost vertical, slightly bulging sides. Gelatinous substance quite thin. 36 to 40 tentacles 

 arise in a single row from the bell-margin. They are equal each to each and are longer than the 

 bell-height. Their basal bulbs are large, elongate, and spindle-shaped, and have dark-purple 

 pigment. There are no other marginal appendages. Velum narrow. Ring-canal simple 

 and unbranched, but the 4 radial-canals give rise each to 15 to 25 pairs of simple, short, 

 unbranched, blindly ending, lateral diverticula. Stomach prismatic with a very short peduncle, 

 and nearly as long as depth of bell-cavity. There are 4 short lips with sinuously folded mar- 

 gins. A row of 4 to 8 elongate, sac-like, sausage-shaped gonads arises from the sides of each of 

 the 4 radial-canals between the sides of the stomach and the feathered (branched) parts of the 

 canals, there being in all 16 to 32 of these suspended gonads. 



Stomach, gonads, tentacle-bulbs, and radial-canals reddish-brown to purple. 



Found on the Pacific coast of California to Washington, and as far westward as the 

 Hawaiian Islands. 



Fewkes found the medusa abundant in bays along the California coast in March and 

 April. He states that when the medusa has 16 tentacles the 4 radial-canals were merely 

 beginning to exhibit notches along their sides and the gonads were beginning to appear at 

 the 4 corners of the stomach. When mature, the medusa has about 36 tentacles. 



