w^^m^m^^mmmm 
THE 
/imerican 
Naturalist 
A MONTHLY JOURNAL 
DEVOTED TO THE NATURAL SCIENCES 
IN THEIR WIDEST SENSE. 
OCTOBER, 1889. 
No. 274 
CONTENTS. 
£ D. Cope, 
.iK ARCHKoLOGY and ETHN(iLOGY OF 
; M.AN1,, [Illustrated] . . Walter Hough, 
•- l'LA(;i.-F/ OF THE UNITED STATES 
5'-T!- \L DihKASES? .... Frank S. Billmgs 
849 
877 
888 
Zoolo,^. - Gastrotricha - Homologies within the 
group of Echinoderms-The Ontogeny of [>ehic and 
Shoulder Girdles-lhe Segments of the Vertebr.ite 
trach^an" from 'the" CatrnTus" Ind Bahamas - The 
Mammalian Carpus— Zoological News; Proto^o.i— 
Arachnidb — Myriapoda— Vertebrata— Fishci— Batra- 
"d Paleontology — Note=; on the Dinosauna 
Embryolo!ry. — 'Y\\^ Development of Murometrui 
a^!:re^atu^, one of the Viviparous Surf-pcrche^On a 
Brood of Lar%al .\mphiuma— The Acquisition .md 
- .tnd Petm^raphv — Petroqraphicnl New- 
/'/7VW, '.,^v — Ihe Am.ncan Fh)Mological Soi-.-ty 
PHILADELPH lA: 
FERRIS BROS., PUBLISHERS 
SI.XTH AND ARCH STREETS 
