His most important anthropological work was his description of sixty human crania published originally in fasciculi under the title Collectionis suae craniorum diversarum gentium illustratae decades (Gottingen, 1790-1828).
In Lingula and Discina the anus lies to the right in the mantle-cavity, but in Crania it opens medianly into a posterior extension of the same.
Elsewhere in the United States fossilized bones, crania of a low order, association of human remains with those of fossil animals are not necessarily evidence of vast antiquity.
These often have the form of prisms of calcite surrounded by a cuti cular meshwork; the whole is nourished and kept alive by processes, which in Crania are branched; these perforate the shell and permit the access of the coelomic fluid throughout its substance.
Wood, Cryptopora gnomon Jeff., Rhynchonella (Hemithyris) psittacea Gmel., Crania anomala Mull., and Discinisca atlantica King.
In Crania it is completely shut off from the main coelom, but in Lingula it communicates freely with this cavity.
When sculptured decorations were added they frequently took the form of imitations of the actual festoons with which it was usual to ornament altars, or of symbols, such as crania and horns of oxen, referring to the victims sacrificed.
Their crania have a normal development; their cheek-bones are high; their noses prominent, with large nostrils; their lips straight; and they are marked by the absence of the auricular lobules.