REPORT ON THE SIPHONOPHOR^. 



10J 



Synopsis of the Families of Calyconectse. 



I. Suborder 



CALYCONECTiE MONOGASTHICiE. 



Cormus represented by a single cormidium, with, a single 

 siphon and a single tentacle. 



Cormidium composed of 

 two medusomes,a sterile 

 and a fertile, without 

 special nectophore, 



Cormidium composed of 

 three medusomes, a 

 sterile, a fertile, and a 

 special nectophore, 



II. Suborder 



Calyconectse polygastrice. 



Cormus represented by a long 

 tubular stem, which bears - 

 numerous ordinate cormidia, 

 separated by free internodia; 

 each cormidium with a siphon 

 and a tentacle. 



One or two nectophores ( A single nectophore, 

 on the top of the < 

 stem. ( Two nectophores, . 



A biserial nectosome on 

 the top of the stem, 

 composed of four to 

 eight or more necto- 

 phores, opposite in 

 pairs. 



Each cormidium with a 

 bract, .... 



Cormidia without bracts, . 



4. Eudoxidae. 



5. Ersaeidse. 



6. Monophyidaa. 



7. Diphyidse. 



8. Desmophyida?. 



9. Polyphyidas. 



Family IV. Etjdoxidje, Haeckel, 1 i 



Eudoxidae, Hkl., System der Siphonophoren, 95, p. 32. 



Definition. — Calyconectse monogastricse, representing a single cormidium, which is 

 composed originally of two persons ; a sterile medusome (siphon with tentacle and bract) 

 and a fertile medusiform gonophore (male or female). 



The family Eudoxidae comprises those monogastric Calyconectse which present in the 

 fully developed and sexually mature state only a single cormidium, composed of two 

 different medusomes, a sterile and a fertile. The sterile medusome is a bilateral medusoid 

 person with three essential and constant organs, a bract (umbrella), a siphon (manubrium), 

 and a tentacle (capturing filament). The fertile medusome is a gonophore with umbrella 

 and manubrium, but without tentacles ; the sexual cells are produced in the wall of the 

 mouthless manubrium. 



Eschscholtz (1, p. 124) in his System of the Diphyidse, distinguished first two main 

 groups in this famdy — I. Monogastricse (" with a single suctorial tube "), Eudoxia, 

 Erssea, Aglaisma ; and II. Polygastricse (" with a long digestive tube bearing numerous 

 suctorial tubes or lateral branches"), Abyla, Cymba, Diphyes. 



Lesson (3, p. 437), adopting the division of Eschscholtz, and collecting the descriptions 

 of other observers (mainly Quoy and Gaimard, 2 and 20), described a greater number of 

 "Diphyidse monogastricse," with not less than nine genera {he. cit., pp. 453-462). 

 Some other species were described by Will (65) and Busch (67). 



The true nature of the monogastric Diphyidse (called usually Eudoxise. sensu ampliori) 

 was not recognised before 1853. In the spring of that year Gegenbaur discovered that 



