The Cambridge natural history . , forming two cones with theirapices directed laterally {Spirifera, Fig. 330), or towards theinterior of the dorsal valve {Atryp)a, Fig. 2), or towardseach other (Glassia); or forming two flat spirals in the sameplane {Koninckinidae). A jugal band is generally present, butvaries much in position, and in some genera lias ,^d^^^^^^ complicated posterior pro-cesses. The lUiyiirli oncllidaeliave no loop or spiralcones, but merely a pairof short crura. The ])rinci])al nioiliti-cations in the attaclimentsof the muscles in the Tistlvdrdinrs are illustrated l»y Prod
The Cambridge natural history . , forming two cones with theirapices directed laterally {Spirifera, Fig. 330), or towards theinterior of the dorsal valve {Atryp)a, Fig. 2), or towardseach other (Glassia); or forming two flat spirals in the sameplane {Koninckinidae). A jugal band is generally present, butvaries much in position, and in some genera lias ,^d^^^^^^ complicated posterior pro-cesses. The lUiyiirli oncllidaeliave no loop or spiralcones, but merely a pairof short crura. The ])rinci])al nioiliti-cations in the attaclimentsof the muscles in the Tistlvdrdinrs are illustrated l»y Productus gigfi?iiriis (Fig. 333),Lcptaena rhonihoidalis (Fig. 334), and Waldhcimiir Jlavescens(Fig. 329). In Irddictiis (Fig. 333) we see in the ventral valve a jiaii- ofdendritic occlusor, often called adductor, impressions and a pairof large fiabellate divaricator impressions. In the dorsal valve thelarge cardinal process served for the attachment of the divari-cator, and a low me(Han s(i)tum se])arated tlie deiKhitic occlusoi-. Fig. 330.—Spirifera drudn. (Carboniferous Lime-stone. ) Showing brachial spires. 502 FOSSIL BRACHIOPODA xars, which are rarely ilivisihle into anterior and posterior pairs. In Lei^taena (Fig. 334) the occhisor scars {a) in the ventral
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
