94 Introduction to Animal Morphology. 



an extension of the endotheca protruded as a pouch 

 through the summit of the gonangium). Gonothyraea 

 has, above the opercular summit of the gonangium, 

 two pedicellate, spherical, medusiform gonophores 

 (meconidia), with 8-20 circumoral tentacles and radial 

 canals. 



This includes the following families : 



i. Campanularidae with terminal, seldom stalked, oper- 

 culate hydrothecae ; hypostome trumpet-like ; blastochemes- 

 (Eucope, Obelia) or sporosacs (Campanularia, Clytia, 

 Hincksia, Laomedea). 2. Campanolinidae hydrothecas ovate, 

 operculate ; polypites cylindrical ; hypostome small, conical ; 

 blastochemes(Campanulina,Calycella). 3. Leptoscyphidce 

 hydrothecse oval ; the ocellated gonochemes an- known as. 

 Liz/.ia, ex. Leptoscyphus. 4. ^quoridce hydrothecae oper- 

 culate, tin- lid of converging lanceolate segments ; blasto- 

 cheines diM-oidal, with (.Mesonema, &c.) or without oral 

 tentui les /V.< iiiorea), and with many radial canals. Stomo- 

 bracliiuin Mnneiiim-s undergoes fission, and has fine retiform 

 canals in the muscular lining of the sub-umbrella ( Wright). 

 5. I.afoeida.- hydrothecae tabular ; polypites cylindrical ; pro- 

 boscis conical, ex. Lafoea. 6. Trachydridcu hydrothecae 

 rudimental ; polypites cylindrical ; proboscis extensile, conical. 

 7. Tliaumantiadaj hydrothecae non-operculate ; hypostome 

 trumpet-like- ; blastochemes, with shallow stomachs; tentacles. 

 often numerous (200 in Tiaropsis), or dissimilar. 8. Cop- 

 piniada} hydrothecx united by an encrusting cellular mass. 

 9. Lineolaridcc hydrotl. sile, tubular, with oviform, 



sessile gonangia. 10. Sertnlariadae sea-firs; hydrothecae- 

 sessile, insi-rted on the stems and branches of the hydro- 

 caulus ; polypites retractile, with one circlet of filiform ten- 

 tacles; sporosacs fixed, n. Haleciida? hydrothecae none, 

 or rudimental, biserial, sub-sessile, joined to a lateral process 

 from the stem ; polypites not, or partly, retractile ; blasto- 

 styles, bearing the sex-products (not in sporosacs), develop 

 within modified single internodes of the stem (pseudogonan- 

 gia), each of which bears a hydranth (A//man), ex. Halecium. 

 12. Plumularidx hydrocaulus bearing, besides the ordinary 



