A treatise on zoology . Fio. XXXVIII. Sphaeronis globulus, after Angelin. 1, from side, ; 2, tegmen, enlarged. species, S. pomum, repro-duced in our Fig. XXXIX.,shows that the number ofbranches visible may betwo, three, oi- four in asingle individual. Eu-cystis, Angelin (1878), Or-dovician, Sweden (), sends its groovesfarther down the thecathan S2)haeronis, over oneor two circlets of thecalplates. From the distalend of each ray a brachiolewas given off, while othersof uncertain number andposition arose along theside of the grooves. Prob-al>ly some of the formsdescribed by S.
A treatise on zoology . Fio. XXXVIII. Sphaeronis globulus, after Angelin. 1, from side, ; 2, tegmen, enlarged. species, S. pomum, repro-duced in our Fig. XXXIX.,shows that the number ofbranches visible may betwo, three, oi- four in asingle individual. Eu-cystis, Angelin (1878), Or-dovician, Sweden (), sends its groovesfarther down the thecathan S2)haeronis, over oneor two circlets of thecalplates. From the distalend of each ray a brachiolewas given off, while othersof uncertain number andposition arose along theside of the grooves. Prob-al>ly some of the formsdescribed by S. A. Milleras Jf(di>rysfitcs should beplaced here ( Tremato-cystis, Jaekel), althoughtheir orals an; not iiyrinKs^ MillercSc (hirley(1894), presents a stage inthe development of food-grooves that in Home respects is more advanceplates have no regular arrangement (Fig. XLII.).. Fin. r», orals CDviTiiig iiiouth ; c;/, section of food-groove runningfrom nioutli to /.;?, brachiole-facets, some of which are jiierreilby ail axial canal ; -Is, plutes clusing nvcr anus ; </, pro-inintMce with two j)orcs, wiiich liDVcn considtMcd gono-poifs; M, ridgo which Lnvcii thought might indicate amadreporlte (or (! may represent d gonopore antihydropore); diplopores surround the wliolc area. although the peristomialAUocystis, Miller (1889), THE CVS TIDE A 73 Silurian, iiulijiiui, may go here. ProteocysHs, Barrande (1887), LowerDevonian, Bolieniia (Fi^^ XLL), (lifFers from SjtJuiero^iiti mainly in the ii--ro^^iilar brancliiiif^of the food-grooves, which stretch farther over the theca,though whetlier the tegmen ever contained more tlian one cycle of ])latescannot be determined from the published figures. Apparently the hydro-pore form
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectzoology
