The porifera and coelentera . straversed by anastomosing canals. It is covered above by a largepneumatophore, provided dorsally with an aurophore; belowthis lies a corona of nectophores. Thje lower part of the coenosarcis covered by cormidia more or less ordinate in arrangement, eachconsisting primarily of a gastrozooid with tentacle, a branchedgonodendron, and a palpon (dactylozooid). ((?) In the Cystonectae (Fig. 49) a large pneumatophore is alsodeveloped, but the family is distinguished by the complete al)sence ofnectophores and hydrophyllia. The coenosarc is long and tubular(Rhizophysa), o
The porifera and coelentera . straversed by anastomosing canals. It is covered above by a largepneumatophore, provided dorsally with an aurophore; belowthis lies a corona of nectophores. Thje lower part of the coenosarcis covered by cormidia more or less ordinate in arrangement, eachconsisting primarily of a gastrozooid with tentacle, a branchedgonodendron, and a palpon (dactylozooid). ((?) In the Cystonectae (Fig. 49) a large pneumatophore is alsodeveloped, but the family is distinguished by the complete al)sence ofnectophores and hydrophyllia. The coenosarc is long and tubular(Rhizophysa), or short and wide (Physalia); in the former casethe cormidia are generally ordinate, in the latter they are arrangedin a multi))le series along the ventral side of the trunk ; they con-sist typically of one or more tentaculate gastrozooids, of gono-dendra, and dactylozooids. 46 THE 11 \ PROM ED USA E Reproduction.—The asexual reproduction of this group isapparently of the nsuul laminar type : medusoids, nectophores, Fio. Kio. ,.1. 40. —l)iat;raiii of Iliysjiliii (iii(ji>or Riirfacf of Vi>lt>lln, Nhuwiiit; inifiiinntoplKirp niul sail (nfliT Cuvior). M.—C()rnii<liiiiii of , willi n goiio<it<iidron (ino(l from Haoi-kol). D, daotylnzooid ; (,, nastrozooid ; HI, ^miic))iii1|miii or diu-tylozooid on tlie >:onod(>ndroii ;Af 9. fpiiiiili inMluNoid, iiltiiiuiti>ly fritHl ; ,U (J. nmU- siKirosai- ; IS, i>iuumatoi)lion-; T, tentaclf(palpacle) of daetylozooid or imlpoii. and (sometimes) hydrophyllia are formed after the maimer .sketchedon p. 20. The development of the fertilised ovum id known only THE HYDROMEDUSAE 47 fioiii ubservatioiis on u few forms which ;ire too widelv ditlereiit toallow of a general developnieiital .scheme being as yet laid plaimla apj)arently always formed ; the first individual liuddcdfioni it may 1>e a i)nenmato))hore (Halistemma), nectocalyx(Ei)ibulia),
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Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectctenophora
