A treatise on zoology . 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
A treatise on zoology . 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 formed a slit between the small gonopore and the niouth ; and thebase, broader than in Spharroiiis, is said to have been prolongcnl into a Fig. XL. Eiicystis raripunctata, oral surface,after Angelin, enlarged. Fig. XLI. Proteocystis flava, oral sur-face, slightly restored from]3arraiide, enlarged. XLII. Mouth and foofl-grooves of IIolo-cystites gyrinus,after Miller & Gur-ley. Its geological age forbids us to regard Proteocystis as a liidi between Sphae-ronitidae and Glyptosphaeridae, but it certainly has points of likeness tothe latter family. Carpocystis, Oehlert (1887), Lower Devonian, W. France,is a simple spheroid with large stem-attachment. Palmacystis, Haeckel(1896), Archegocystis, & Codiacystis, Jaekel (1899), are forms with theepithecal branched food-grooves, described by Barrande as hydrophorespalmees of Piracystis, Craterina, & Aristocystis. Family 2. Glyptosphaeridae. Diploporita in which the food-groovesextend over the theca well beyond the adoral circlet, and irregularlytransgress the sutures between thethecal plates. Diplopores diffuse. Bt-. These represent a further advanceon the type of struct
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectzoology
