520 



MEDUSAE OF THE WORLD. 



Caprla, Llpkea, Lucernaria and Haliclystus represent the more simply organized Eleuthero- 

 carpidae. A clear understanding of these relations can best be obtained from a study of the 

 figures by Gross, 1900 (Jena. Zeitsch. fiir Naturwissen., Bd. 33, p. 613, taf. 23, 24). Being 

 internal characters, I have not made use of them in the classification of the Stauromedusae. 



As one would expect in sessile animals the Stauromedusae show evidences of degeneration, 

 loss of marginal lobes or of tentacles; and in none of them do we find the lithocyst-bearing 





Gelatinous substance '. : .'-:"-:-:':'. : :: : .0.-V. : 





' 







\ N f c 



Im. J 











FIG. 332^. Median longitudinal perradial sections and cross-sections of Stauromedusse. Somewhat diagrammatic, after Gross. 



A. The internal anatomy of the Cleistocarpida; illustrated by Cralerlophus leihys. 



B. The internal anatomy of Eleutherocarpida 1 illustrated by Haliclystus. The cross-partition, or claustrum (C), is 



found in the Cleistocarpidae but is absent in the Eleutherocarpidae. 



In both figures: C, transverse partition spanning between gonads; ex, outer chamber; fc, funnel-pits containing 

 longitudinal nucleus; g, gonads; gt, gastric cirri; Im, longitudinal muscles; s t interradial septa. 



sense-organs seen in all other orders of Scyphomedusae. Eyes and "otocysts" are absent in 

 the Stauromedusae, and pulsation is not exhibited by the sessile forms. 



There is reason to believe that the Stauromedusae are the most degenerate of all Scypho- 

 medusae and are to be regarded as sexually mature Scyphostomae (see Kassianow, 1901; 

 Goette, 1887). Their degeneracy is amply accounted for by their sessile mode of life; Hornell, 

 1883 (Natural Science, London, vol. 3, p. 204), and Hurst (Ibid., p. 209) believe that they are 



