234 THE VOYAGE OF H.M.S. CHALLENGER. 



Siphosome. — The composition of the siphosome, and especially the arrangement of the 

 crowded cormidia along the median ventral line of the vesicular and spirally convoluted 

 trunk, is in the Epibulidse very similar to that in the Discolabidse. If the nectophores 

 of Physophora or of Discolabe were detached and the stem contracted, and if the apical 

 float were inflated, the external appearance would be nearly the same as in Epibulia. 

 The corona of large projecting palpons which surrounds the base of the nectosome and 

 covers the siphosome is also very similar. It may even be that the composition of the 

 ordinate cormidia, and their arrangement around the segmented shortened trunk, is 

 very similar in both groups. But a closer examination informs us that this simil- 

 arity is a mere analogy, not a true homology; the typical structure of the single 

 persons and organs (mainly of the pneumatosac and the gonodendra) is in the 

 Epibulidse very different from that in the Discolabiclse, and agrees with that in the 

 other Cystonectse. 



Synopsis of the Genera of Epibulidse. 



Tentilla simple, filiform, undivided, ........ 73a. Epibulia. 



Tentilla tririd at the distal end, with an odd median terminal ampulla and two paired 



lateral horns, .......... 736. Angela. 



Genus 73a. Epibulia^ Eschscholtz, 1829. 

 Epibulia, Esch., System der Acalephen, p. 148. 



Definition. — Epibulidse with simple filiform tentilla, each representing an undivided 

 lateral branch of the tentacle. 



The genus Epibulia was founded by Eschscholtz (1, p. 148) for the reception of two 

 very different Cystonectse, viz., (1) the Mediterranean Rhizophysa filiformis, Lamarck 

 (described by Forskal in 1775 as Physophora), and (2) Rhizophysa chamissonis, 

 Eysenhardt, from the North Pacific (77, p. 40, Tab. xxxv. fig. 3). Since the name 

 Rhizophysa is now generally accepted for the former, we retain the name Epibulia for 

 the latter. Another species, closely allied to this, was afterwards described by Brandt 

 as Epibulia erythrophysa (25, p. 34). The excellent figure of this Pacific species, 

 which Mertens had painted from life, but which, alas, was never published, leaves no 

 doubt that it belongs to this genus, and that it is closely allied to the new Indian species 

 which I myself observed living in Ceylon, and which is described in the sequel as 

 Epibulia ritteriana, dedicated to the highly esteemed protector of phylogenetic science, 

 Dr. Paul von Bitter of Basel (PI. XXII. figs. 6-8). 



Considerable confusion in the nomenclature of this genus (as also of other genera 



1 Epibulia = Artful, iirifyiijhtit.. 



