551 
verstärkt, und für die „tiefe“ Ausatmung war die nötige Innervations- 
intensität momentan nicht mehr vorhanden. 
Die den verschiedenen Atmungsphasen entsprechenden Linien (auf 
dem Schirme) verlaufen, grob genommen, alle in ziemlich gleich- 
mäßigem Bogen vom Zwerchfellherzwinkel zur lateralen Brustwand. 
Der Winkel, welchen der Zwerchfellschatten mit der Projection der 
knöchernen lateralen Thoraxwand bildet, bietet keine sehr erheblichen 
Differenzen dar. Höchstens sieht man bei sehr angestrengter Aus- 
atmung eine bedeutendere Wölbung der seitlichen Zwerchfellpartien 
und dementsprechend einen mehr spitzwinkligen Anschluß derselben an 
die Thoraxwand eintreten. Dafür schießt aber bei tiefer Einatmung 
jener Winkel tiefer herab. 
(Schluß folgt.) 
New York Academy of Seiences. 
Biological Section, April 5, 1897. 
Prof. Osporn reported upon the phylogeny of the early Eocene 
Titanotheres, showing that they are divided into two distinct series 
included under the genera Telmatotherium and Palaeosyops, both of 
which independently acquired horns. The Telmatothere line begins with 
T. boreale, a form which Corr referred to as Palaeosyops. It is 
distinguished by animals with long narrow skulls and high stilted feet, 
and undoubtedly represented the upland types of the family, The 
Palaeosyops line, as suggested by Earte and Harcuer, passes through 
P. laticeps and P. manteoceras and Jeads up to Diplacodon, the 
larger species of which surpass in size the smaller Titanotheres of the 
Oligocene. This main line gives off several collaterals, such as P. palu- 
dosus. Lambdotherium does not belong in the Titanothere phylum at all. 
A second note related to a division of the two groups of placental 
mammals, the Mesentheria and Ceneutheria. The former, since WorTman’s 
demonstration that the Ganodonta are ancestral Edentates, must now 
embrace this division, besides the Creodonta, Lemuroidea, Tillodontia, 
Insectivora, Amblypoda and Condylarthra. 
The third note related to the origin of the typical mammalian types 
of teeth among the Theriodonta, Cynodontia and Gomphodontia of the 
Triassic. It is especially noteworthy that the Gomphodontia afford a 
demonstration of the origin of multituberculate teeth from a trituberculate 
ground plan, as hypothetically assumed by the speaker some years ago. 
Mr. Brapney B. Grirrin reported that in Thalassema (one of the 
Echiurids) the spireme occurs in minute ova (3 micra in diameter) floating 
in clusters in the body cavity. The spireme segments into one half the 
somatic number of chromosomes, which by partial longitudinal splitting 
