. Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. strong callosity extendsacross the rostral cavity, but does not reach to the exterior margins. From thiscallosity, a slender mesial septum extends half way to the base of the shell : oneach side of this are the muscular impressions. The interior of the dorsal valveshows the cardinal process extending in a low rounded mesial septum whichreaches below the middle of the shell, each side marked by a distinc
. Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. strong callosity extendsacross the rostral cavity, but does not reach to the exterior margins. From thiscallosity, a slender mesial septum extends half way to the base of the shell : oneach side of this are the muscular impressions. The interior of the dorsal valveshows the cardinal process extending in a low rounded mesial septum whichreaches below the middle of the shell, each side marked by a distinct foveal plates are narrow and very divergent. This genus possesses characters somewhat intermediate to Tropidoleptfs andLeptocgelia, when we consider the general form of the shell, but differs from bothin internal structure. The strong dental lamellae and dental processes extend fromthe lower angles of the area; while in Tropidoleptus, the teeth are oblique,crenulate, and distinctly separate from the area. Fig. 1. Exterior of the dorsal valve, showingthe pustulose surface: enlarged. Fig. 2. Interior of the ventral valve, enlarged:tt, teeth; 00, the thickened No. 89.] 73 Geological relations. The single species known occurs in the Hamilton group,associated with other Brachiopoda, but extremely restricted in its vertical range. OBSERVATIONS ON THE GENERA ATHYRIS (= SPIRIGERjl),MERISTA ( = CAMARIUM), MERISTELLA AND LEIORHYN-CHUS. Among- the fossils referred for many years to Terebratula, Atrtpa, etc.,European authors have separated the Genera ATHTRisaud Merista; shells whichhave many characters in common, and which were indeed at first united underSpirigera or Athtris, until in 1851 the Genus Merista was proposed by In my later studies of the Brachiopoda of the American palaeozoic strata,I have referred to the Genus Athyris certain species which have a subglobose orovoid form, with lamellose surfaces, and without, or with scarcely perceptib
Size: 2415px × 1035px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, booksubjectscience, bookyear1853
