]32 The American Gr.eologst. February, 1894^ 
idee. The slight introversion of the pauci-spirals in this genus should 
not be given too great taxonomic value towards the Atrypidce. 
In connection with Cyolospira, forms are discussed which served 
Winchell and Schuchert as the types of their genus Hallina. These- 
species, Zygospira nicolleti and Z. saffordi, differ from Cyclospira not 
in the direction of the Terebratulidoe, as was at first supposed, but are 
now known to be clearly related to Zygosjrira, of which they are mature 
species, neither being an immature stage of Z. recur virostra. Z. nicol- 
leti is regarded as synonymous w T ith Atrypa exigua, Hall, upon which 
is founded Protozyga, subgen. nov. It has recently been 6hown (Proc. 
Biol. Soc. Washington, vol. vni, pp. 71-82) that Z. saffordi is a more pro- 
gressive fixed form towards Z. recurvirostra than is Z. nicolleti. 
Moreover, since the generic characters of these species are in harmony 
with Anazyga, Davidson, an admitted synonym of Zygospira, it is not 
clearupon what characters Protozyga istostand. Since these stages came 
into and passed out of existence rapidly and do not have the same value 
as the fixed stages of development in the Terebratulidai, there can be 
no great taxonomic value attached to them. 
Clintonella, gen. nov. (type C. vagabunda, n. sp\), is supposed to be 
intimately related to Zygospira, but the nature of the spirals is unde- 
termined. 
Atrypina, gen. nov., is based upon Leptocoeiia imbricata, Hall, and 
includes a few forms previously referred to Cozlospira. One of these is 
the well-known European shell, Atrypa barrandi. Atrypina is clearly 
a permanent condition of one of the later ontogenetic stages of Atrypa. 
The work of Friele, CEhlert and Beecher on the Terebratellidai has 
shown that it is not safe to propose new genera upon single specimens 
nor upon a number of specimens apparently, but really not adult. The 
spire-bearers are no exception to this statement, since we now know 
that Zygospira also passes through a series of metamorphoses. These 
remarks apply more directly to those genera of the Helicopegraata 
which are based upon the modifications of the loop processes. 
For the present work, paleontologists, more particularly those making 
a special study of the Brachiopoda, owe Hall and Clarke a debt of grat- 
itude. Any one who has tried to develop thebrachidium inbrachiopods, 
whether by the aid of acid, sections or pen-knife, will fully understand 
the difficulties here so successfully overcome. It is evident that the 
volume when completed, will be a most valuable storehouse of brachio- 
pod knowledge, far outranking all previous works of a-similar nature. 
Charles Schuchert. 
PERSONAL AND SCIENTIFIC NEWS. 
J. B. Tyrrell, of the Geological Survey of Canada, and .1. 
W. Tyrrell, Dominion government land surveyor, have recently 
returned to Ottawa from an expedition to the far north. They 
went as far as Chesterfield Inlet, on the northwest side oi 
