Review of (Recent Geological Literature. 327 
special study of them, and the mere assertion that they are un- 
rehable, can have no effect in delaying the adoption of internal 
peculiarities as of the first importance in their systematic classi- 
fication. 
He who condemns internal characters as a basis of classifica- 
tion in the bryozoa cannot stop there, but, to be consistent must 
also carry his condemnation to other classes of animals in whose 
arrangement they constitute important factors. But we ask, who 
would for a moment think of overthrowing the admirable system 
proposed by Zittel for the sponges (which rests entirely upon 
minute internal characters) for the extremely artificial classifica- 
tion previously in vogue? Or, who would say that because it 
is generally difficult to determine the interiors of fossil brachio- 
poda, the arrangment and form of the spirals and other inter- 
nal features of the shells should not be accorded great classifica- 
tory value? vSimilar questions relating to the value of pallial 
and muscular impressions, and the hinge peculiarities of the 1am- 
ellibranchiata, the arrangement of the septa and other features 
of the rugose corals, (all strictly internal characters) might be 
asked were they necessary, but, fortunately, scientific inquiry 
has advanced so far that to call them in question is to insult our 
highest authorities on those branches of natural history. 
REVIEW OF RECENT GEOLOGICAL LITERATURE. 
/w the Geological Magazine for February the Rev. Norman Glass, long 
the associate of the late Thos. Davidson in his labors on the British fos- 
sil brachiopoda, describes the position of the spirals in these shells. In 
the spiriferids he says the spirals have their bases facing each other in 
the center of the shell but their apices point a little upwardly toward the 
hinder end of the lateral margin. In some Cyrtinas they are directed 
backw-ard into the rostral cavity as well as upward. 
In all the other spiral-bearing brachiopods the spirals are so arranged 
that a section made transversely through the shell at its greatest circum- 
ference would cut the apices and the centers of the bases of the spirals. 
Thus, in Athyris the spirals face each other in the center, and their apices 
point directly away from one another toward the lateral margins. If 
they are rotated — both outwardly — about antero-posterior lines passing 
