1884.] 5 Zodlogy. 205 
evidence as to the function which the author was able to obtain, 
was that when the back is mechanically irritated the animal turns 
up its ventral surface and the disks become covered with the 
Sa object of which seems to be retaliation.— Fourn. R. 
. Soe. 
ALBRECHT ON THE MORPHOLOGICAL VALUE OF THE MANDIBU- 
LAR ARTICULATION.—In this pamphlet M. P. Albrecht combats 
the general idea that the ear-bones are homologous with different 
parts of the first, or first and second visceral arches—parts which 
are distinct bones in the lower gnathostomes. His argument is 
as follows: In all non-mammalian gnathostomes the articulation 
of the mandible is between the articular element and the quad- 
rate, and good evidence is needed to the contrary before we are 
bound to believe it otherwise in mammals. He maintains that 
the squamosal is a compound bone, formed of the true squamo- 
sal and the quadrate, and that the mandibular articulation is with 
the latter element, just as in other gnathostomes. This belief is 
new-born infant’s skull in the writer’s possession. In this skull 
the temporal of the right side is normal, but on the left side the 
zygomatic part is isolated from the true squamosal, which is united 
with the ali-sphenoid. Cases of a sutural division of the squamosal 
into an upper and lower portion are cited. If then, the zygomatic 
Part of the squamosal is really the quadrate, and the mandibular 
articulation i i i 
— €ar bones must be sought for. After enumerating and 
Maat. with the single cartilage of the urodela; and in the 
Ror the four tiny ear bones are identical in position and 
of Rega that have no columella. The extra-mandibular part 
tachi” and with the columello-articular ligament of the Ba- 
throughone Sauropsida. Thus the arrangements are the same 
fishes} 
j Sauropsida and Mammals. 
