eB 
__ do not doubt that we will find in young specimens of Amia 
_ Ontology has shown that in some fishes allied to Amia alt 
_ posterior dorsals these processes become smaller, 
_ the ribs unite below. The processes begin to disappeat 
-ribs are now articulated directly with the free intercentre. 
The so-called untere Bogen, lower arches, or hemap" 
= OE Amia, are therefore really the ribs. 
_ pleural Spines, are homonomous to the neural spine» 
942 General Notes. 
- Audubon’s “ Birds of America” is correct. The hollow cy indes 
exist, but each horny tube is completely filled by the carti 
nous rod of the glosso-hyal element, and hence cannot be used! 
sucking. The tongue is, on the other hand, an instrumenti. 
the prehension of small insects. Dr. Schufeldt further s 
that in not a single cephalic structural particular do the hus 
ming-birds agree with the swifts. ¥ 
On the Morphology of Ribs..—Embryology has shown! 
the ribs are developed defween the mesoblastic somits; they af 
therefore intervertebral. 
The problem now is, how the different modifications of 
position and structure of the ribs derived from that ori 
condition. 
If we carefully examine the skeleton of Amia, one of t 
living Ganoids of this continent, we observe the following: 4 
x 
terior disk and a posterior one. The anterior represents 
centrum proper, the posterior the so-called intercentrum. 
vertebre show the characters of the caudals of that form fa 
dorsal vertebrz divided by a suture separating a verte g 
anterior centrum proper and the posterior intercentrum. of 
In iat 
the dorsal vertebre the rib is connected with a process © 
Posterior parts of the centrum,—that is, the nie 
u gi 
are always connected with them. From the thirty- si 
i In the first caudal vertebræ we find free spines con ed to 
the distal part of the united ribs; these are co-ossified 19 
from the forty-seventh vertebra. the 
_ As the ribs or pleural arches are homonomous tO be 
Pophyses, or pleural arches, these spines which my. both 
ment of 
A * A paper read before the American Association for the Advan 
ugust, 1887. . ' 
7 According to a verbal communication of Professor Zittel. 
