1895.] Zoology. 855 
take place during November, December and January. The author is 
inclined to think that there is a migration connected with either the 
spawning act or the hatching out of the ova. The mature female crab 
is usually 64 inches in size, while males, are mature when much smaller. 
(Proceeds. Roy. Soc., Edinburgh, Vol. XX). 
The Odonata of Lower California.—Various collections of 
Dragon-flies from Baja California have been acquired from time to 
time by the California Academy of Sciences, and these form the basis 
for a memoir recently published by Dr. Philip P. Calvert. The total 
number of specimens examined is 2600, representing 40 species, of which 
6 are new. Of these species, 9 are distributed over a considerable part 
of temperate America; 18 are neotropical, and 18 nearctic in distribu- 
tion, while 3 of the species described as new are, according to present 
knowledge, restricted to Lower California. One of the objects of the 
paper is to determine the amount of variation in structural details, es- 
pecially in the venation of the wings, assumed to be of generic charac- 
ter. These variations are to be found under the respective species. 
Three page plates, containing 125 figures, accompany the descriptions 
of the species. (Proceeds. Cal. Acad. Sci. (2) IV). 
Baur on the Temporal Part of the Skull,’ and on the Mor- 
phology of the Skull in the Mosasauridae.’—In the first paper 
Dr. Baur reviews the work which he has done in the difficult analysis of 
the temporal region of the reptilian skull, in former years, and what 
has been done since by other authors. His results may be summed up 
as follows. The question relates principally to the determination of 
the three elements that connect the quadrate bone with the skull su- 
periorly and anteriorly. These have usually, says Baur, been termed 
the squamosal, supratemporal, and quadratojugal. He adopts this no- 
menclature for the first and third, but wishes to replace the second by 
“prosquamosal”’ of Owen. This is because the name supratemporal 
was used previously for a different element peculiar to the Teleosto- 
mous fishes. The present reviewer has called the three bones in ques- 
tion, the parooapital, ald ta acre and sJgomane, after earlier au- 
shoes Baur t which he,with some other authors 
calls the squamosal, is not homologous with the paroccipital of the tor- 
toises and Ichthyosaurs, as I have supposed. He agrees with those au- 
' Remarkungen ueber Die Osteologie der Schliifengegend der höheren Wirbel- 
thiere. Anatomischer Anzeiger, X, 1894, p. 316. 
? The American Journal of Morphology 1894, p. 1. 
