592 



MEDUS/E OK TIIK WOULD. 



GENERIC CHARACTl-RS. 



Cyaneidaewith 8 marginal sense-organs and wirli S acliaclial clusters of marginal tentacles. 

 The tentacles of each cluster may arise in several rows from the siilnimhrelia surface. There 

 are 8 chief lohes and i6 to 32 secondary lappets. Without radial-muscles in the lobes. 



The names Couthotiyia andMcJorti are preoccupied, but Agassiz's Desmonetna may be used. 



The oldest species is the little-known " Clirvsoorn" aniidn luiiiJii erroneously described 

 by Lesson, 1829 (Voyage de la Co'/tiill,-. Zooph., p. 1 14), from the region of Cape 1 lorn. South 

 America, and recently revealed through the studies of Maas, 1908. 



Some of the medusas which Haeckel included in his genus ''Desinonema" represent only 

 immature Cyancas in which the tentacles of each cluster arise in a single row. VanhofFen, 1888, 



Fig. ■^qb.—Dnmonemii f^ituilkUaudii, afiiT Maas, in Mcdviscs Expi'ditinn Antarcticquc Frangaise. 



shows, however, that' there are considerable anatomical differences between Cyanea in any 

 stage and Desmonema. In Desmonema, for example, the 8 clusters of tentacles arise in linear 

 arcs concentric with the general contour of the bell-margin, whereas in Cyanca they arise in 

 crescents, the horns of which are directed outward toward the margin. Moreover, there are 

 no radial-muscle strands in the 8 velar lobes oi Desmonema, but these are found in Cyatiea. 



Desmonema annasethe Haeckel is clearly a young Cyanea, as was pointed out by Van- 

 hoffen, 1888. 



The rediscovery of Lesson's. Cape Horn, medusa hv Maas makes it practically certain 

 that it is specifically referred to by Agassiz, 1862, p. 118, under the designation Couthouyta 

 pendula. 



