* ' Horse Tergestina?/ 1844, p. 77, Taf. ii. fig. 22. 



f 4 BeobachtuDgen \iber Anatomie und Entwickelungsgesehichte 



einiger wirbellosen Seethiere/ 1851, p. 46. 





1 54 Dr. C. Chun on the Siplionophora. 



may designate Monophyidae, and the same clustered arrange- i 



ment of the polymorphous individuals was detected upon their I 



stems, it seemed probable that in these also the groups would 

 separate. Claus demonstrated in his interesting memoir that 

 the monogastric colonies described by Gegenbaur under the 

 name of Diplophysa really represent the freed sexually mature 

 offspring of Monophyes. 



Consequently, so far as our knowledge of the cyclical process 

 of development of the Monophyidse and Diphyidse on the one 

 hand, and on the other of the highest Siplionophora, namely 

 the Velellidae, extends, we were justified in assuming that the 

 brood of the Eudoxice and Diplophysw, like the Medusae j 



budding and separating from the Velellidae, namely the Chry- 

 somitrce, in their turn furnish the polymorphous nurse-gene- 

 ration. 



To my astonishment, however, the study of a new species 

 of Monophyes showed me that the cyclical development of the 



Siplionophora manifests still further complications. 



In briefly describing now the structure and development of 

 Monophyes primordtalts, which is the name I give to this new 

 species, I only follow the course which my investigation 

 took. 



Among the. rich pelagic fauna of Malaga with which the 

 use of the surface-net furnished me I often remarked a small 

 Siphonophoran stock which looked remarkably like a Diphyes. 

 It is true that in all the specimens a second lower nectocalyx 

 was wanting, a circumstance which, however, did not much 

 strike one at first, seeing that, when at all roughly treated, both 

 nectocalyces of the Diphyidse easily become detached. But 

 although I proceeded most carefully in their capture, I never 

 succeeded in detecting a colony with the missing second necto- 

 calyx. As, further, it was impossible to discover any point 

 of insertion for the latter, I arrived at the conclusion, which 

 was afterwards confirmed, that I had to do with a Monophyid 

 of very aberrant structure. At first I regarded it as new, 

 but subsequently ascertained that two excellent old observers, 

 Will and Busch, had observed and figured this Siphono- 

 phoran stock. Will * discovered it at Trieste, and, like 

 Busch f and later observers, regarded it as a Diphyes. He 

 named it Diphyes Kochii ; and under this name it was also 

 more accurately described by Busch, with the express remark 

 that he had been no more successful than its discoverer in the \ 



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