288 General Notes. { March, 
ZOOLOGY. 
THE PROATLAS, ATLAS AND AXIS OF THE CrocopiLia.—l. Pro- 
atlas—In all Crocodilia there is developed an osseous piece be- 
-tween the skull and the neurapophysis of fe atlas. This piece 
is called * ‘kleines niedriges Bogenstiick” (Meckel?) ; “ lame. trans- 
verse’ any ; “oberes Schluss-Stiick ” (Stannius’) ; aes oberer 
Bogen ” (Bruch*) ; “ Spinal — oder Dachstiick ” (Brühl’) ; PERE 
ral spine of the atlas P (Owen®) ; “ proatlas ” (Albrecht’) ; “ post- 
occipital bones ” (Marsh8). 
ruch (l. c., 1861) was the first to give the correct explanation 
of this piece, he considers it as the neurapophysis of a vertebra, 
| between the skull and the atlas. 
oe) In 1880 Albrecht? reached the same result (I. c.). 
7 Brühl and Marsh consider the elements in question as belong- 
ing to the skull: Dollo® has shown in extenso that this view is 
Wrong, and that the ‘“ postoccipital bones” really represent 
i “ proatlas” of Albrecht, and therefore parts of the vata 
: column, 
iy Eudes- eee a says that it “ représente larc postérieur 
de l’atlas chez Phom 3 
Dollo (1. c.) has irea a list of vertebrates in which the “ pro- 
atlas” has been observed; it is not necessary to repeat it. 
I have to add only some few points : 
1. The proatlas is developed from two different cartilages €x- 
S Pri in the same way as all neurapophyses d 
oe he two parts may be distinct in the young animals, an 
even in adult ones? Ina nearly ripe embryo of /acare vallifro ae 
I find two elongated osseous elements. Ina young Aligator 
__| Meckel, J. F. System der vergleichenden Anatomie, 2 ter Theil. Abth. 1 
Halle, 1824, p. 430. 
A abi St ti 
_ * Bruch, C. Vergleichende pand des Rheinlachses, Mainz, 1861, p. 134- 
-é Brühl, C.. B. Ico es ad zootomiam illustrandam, Das Skelet der Kyocodilinen, 
Ges, 1862, pp- 2-3. 
6 Owen, On the mony of Vertebrates, Vol. 1, p. 65, L 1866. Atlas 
ee T Albrecht, P. Ueber di oatlas, einen zwichen dem Cio tok dem 
+ der amnioten Wirbelthiere ekba Wirbel, ri arah a 1880, p. 475- a 
ra O. sthiere g pans acters of Am n Jurassic Dinosaurs, Part 
on of Brontosaurus, Am: J..Sc., Vol. xx iag Au ug., 1883, pP- 3- ës 
lei is a believed that Albrecht first chines d the true nature of these bon 
‘but, as s L have ve said, Bruch already had the same idea miiy twenty years 
sa Dollo, LG inquieme note sur les an de Bernissart, Bull. Musée Roy- 
- Hist. Nat. Belg., bies II, 1884, pp. 129-135. 
~ H Eudes-Desion mps, Mém teas sur les Téléosauricus de époque jurasst AY 
du tinct es rg Calvados. Mém. Soc. Linn. Normandie, Vol. x11, Caen, I 3 
peat TH Á manual of the > anatomy of vertebrated animals. Lai 
