BRACHIOPODA 



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brian : the Ostracoda, little bivalve forms, whose shells look 

 deceptively like those of molluscs ; and the Phyllopoda, which 

 have a large shield on the head and thorax, and a many-jointed 

 abdomen. 



American Cambrian Fossils 



i. Lingulella coelata, 2/1. (Walcott.) 2. Agnostus interstrictus, 3/1. (Walcott.) 

 3. Conocoryphe Kingi. (Meek.) 4. Elliptocephalus Thompsoni. (Walcott.) 

 5. Olenoides typicalis. (Walcott.) 



Brachiopoda. — These are among the most abundant of Cam- 

 brian fossils ; most of them belong to the lower order of the class 

 (I?iarticulata), in which the shells are mostly horny and the two 

 valves are not articulated together by a hinge. The horny-shelled 

 Discina and Lingulella are of great interest, for they have per- 

 sisted through all the changes and vicissitudes of the earth down 

 to the present day, with hardly any modification. The second 



