A treatise on zoology . bears only three 2, Callocystinae, starts from a form in which all five sub-vective grooves, with the usual flooring plates and brachioles, pass overthe theca, as in Lepadocystis ; and diverges (a) by suppression of grooves,without branching, into Le^jadocrinus and Pseudocrinus ; (6) by branchingof grooves, with subsequent suppression, into Callocystis, ^phaerocystis^ andStrobilocystis; pectinirhombs 1 &5, 14 & 15, 12& 18 probably alwayspresent. Genera — Lejxi- @ © Q. docystis, P. H. Carpenter(1891 ; syn. Aleekocystis,Jaekel, 1899), Ordovician,Indi
A treatise on zoology . bears only three 2, Callocystinae, starts from a form in which all five sub-vective grooves, with the usual flooring plates and brachioles, pass overthe theca, as in Lepadocystis ; and diverges (a) by suppression of grooves,without branching, into Le^jadocrinus and Pseudocrinus ; (6) by branchingof grooves, with subsequent suppression, into Callocystis, ^phaerocystis^ andStrobilocystis; pectinirhombs 1 &5, 14 & 15, 12& 18 probably alwayspresent. Genera — Lejxi- @ © Q. docystis, P. H. Carpenter(1891 ; syn. Aleekocystis,Jaekel, 1899), Ordovician,Indiana (Fig. XXVIIL).Theca ovoid; plates aroundanus slightly altered fromthe archetypal on 1 & 5,12 & 18, 14 & 15, and10 & 15. Main groovesfive, stretching a short dis-tance over theca, one toeach plate of fourth , Mather(1843?; Conrad, 1840; Hall, 1859: synn. Ajnocystis, Forbes, 1848;Staurocystis, Haeckel, 1897; 1 Hallicystu, Jaekel, 1899; includes. Fig. XXVIII. Analysis of Lepadocystis Moorei, based on Jleeks figures(1871 & 1873). Plates 15 to 19 notched by food-grooves ;liydropore on plate 23. 62 THE CVS TIDE A Pseudocrinus quadrifasciatus and P. ohlongus), Silurian, North America,England, Scandinavia (Fig. XXX.). Plates raucli as in onl& 5, 12 & 18, 14& 15 only. Main grooves four,the anterior being aborted, extend over theca to a degree that differsin different species, and is always less in younger stages. Pseudocrinus,
Size: 2031px × 1231px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectzoology
