. Bulletin of the British Museum (Natural History). EVOLUTIONARY TRENDS IN CAPITATE HYDROIDS AND MEDUSAE 513 Rosalinda tvilliami Totton As in Zanclea the hydranth is t3'pically corynid with numerous scattered capitate tentacles. The chief interest of the species lies in the fact that it has an encrusting base from which the hj-dranths arise. This encrusting base is believed to have an internal mesogloeal skeleton as in the Solanderiidae. The reproduction of this species is not known. Dendrocoryne misakinensis Inaba The simple Corynid hydranth is found here also but in other respects this speci
. Bulletin of the British Museum (Natural History). EVOLUTIONARY TRENDS IN CAPITATE HYDROIDS AND MEDUSAE 513 Rosalinda tvilliami Totton As in Zanclea the hydranth is t3'pically corynid with numerous scattered capitate tentacles. The chief interest of the species lies in the fact that it has an encrusting base from which the hj-dranths arise. This encrusting base is believed to have an internal mesogloeal skeleton as in the Solanderiidae. The reproduction of this species is not known. Dendrocoryne misakinensis Inaba The simple Corynid hydranth is found here also but in other respects this species is one of the most advanced Capitate hydroids. There is an upright, branched gelatinous skeleton completely covered in ectoderm. The gonophores are not borne on the hydranths but on the rhizocaulome formation. Ptilocodium repens Coward This is an aberrant form found on the leaves of the pennatulid Pennatida fimhriata Herklots. The gonophores are borne at the base of the hydranth and are fixed eumedusoids with four radial canals and a ring gonad (Text-fig. 55).. Fig. 55. Ptilocodium repens Coward, an aberrant Corynoid with a nutritive zooid and a dactylozooid (redrawn from Leloup, 1940). The specialized features are many : the coenosarc is naked and encrusting, the sessile nutritive polyps have no tentacles, and there are sessile dactylozooids with four short capitate tentacles. This species is insufficiently known but it may have a common origin with the ancestors of Millcpora. Another interesting feature is the division of labour in the polyps, the one concerned with feeding and reproduction and the other with protection. (b) Relationships The division of the athecate hydroids into Capitata and Filifera by Kiihn (1913) was a great advance on earlier classifications, and, if we omit species later removed. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustration
Size: 1893px × 1321px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., 1957, boo, bookauthorbritishmuseumnaturalhistory, bookcentury1900
