. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. Text-fig. 27. Larva of Agalma okenii from the Gulf of Aqaba, 'Manihine' St. 1, x 23. on the facts that they have trifid tentilla like Agalma spp. and that the bracts differ from those of the only other Agalma species elegans, but agree with those figured by Haeckel for Crystallodes rigidum ( = Agalma okenii). The three interesting monogastric larvae bearing larval bracts and a larval type of tentillum were taken at 'Manihine's' Aqaba Station Ai made on 31 December 1948 in 15 fathoms. The smalles
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. Text-fig. 27. Larva of Agalma okenii from the Gulf of Aqaba, 'Manihine' St. 1, x 23. on the facts that they have trifid tentilla like Agalma spp. and that the bracts differ from those of the only other Agalma species elegans, but agree with those figured by Haeckel for Crystallodes rigidum ( = Agalma okenii). The three interesting monogastric larvae bearing larval bracts and a larval type of tentillum were taken at 'Manihine's' Aqaba Station Ai made on 31 December 1948 in 15 fathoms. The smallest of the tentilla measured about 0-2 x 0-13 mm., having three tiny processes at the distal end, one turn of the cnidoband, and a number of nematocysts (0-01-0-06 mm. long) set obliquely at the base (cf Lens & van Riemsdijk, 1908; fig. 98, pi. xm, 'type 1'). Dawydoff (1928) has given a warning that accounts of siphonophore development prior to those of Metchnikoff must be treated with caution. This warning should be extended to Dawydoff's own short summary, which contains false statements as well as interpretations. The remarkable allegation by Haeckel (1869 a) that the pneumatophore originated as a diverticulum of the common' Primitivhole' was by implication denied in 18886, when he said that in all cases the pneumatophore arose as a gland- like invagination of the exoderm. It is very difficult to see the structural details of these siphonophore larvae when they are alive, except in the early stages. I am concerned here only with the larval bracts figured by Haeckel. They have a shape that is characteristic, and is shown in lateral view by Haeckel's (1869 a) plate vn, fig. 51. The upper and outer faces are nearly at right-angles to one another, and the outer face is divided by a longitudinal ridge into two facets (Text-fig. 27). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and ap
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Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
