ZOOLOGi^ AND BOTANY, MICROSCOPY, ETC. 543 



and the rabbit. The similarities aud differences between the cranial 

 muscles of Monotremes, Marsupials, and Eutheria are dealt with. In 

 many particulars of the cranial musculature adult Monotremes are more 

 primitive than Marsupials and Eutheria, but some of the t;ranial muscles 

 in Monotremes exhibit special transformations. Marsupials are more 

 primitive than Eutheria in regard to certain respects of the cranial 

 musculature. Certain developmental changes which, on comparison 

 with Monotremes, appear to be of importance in the phylogenetic history 

 of the cranial muscles of Marsupials and Eutheria occur in the pouch 

 stage of Dasyurus, but are omitted or slurred over in the development 

 of the pig and rabbit. 



Skull of Chrysochloris.* — R. Broom has studied sections of the 

 head of a young specimen of Chrysochloris hottentota and a prepared 

 skull of a slightly older skull of C. askitica. He finds that the skull 

 of this interesting type is in part primitive, and in part specialized and 

 degenerate. It is primitive in the structure of Jacobson's cartilage, in 

 the feeble development of the inferior turliinal, in the simple columella- 

 like alisphenoid, in having a large maxillary zyg^^matic process, in the 

 possession of a large complicated pterygoid which articulates with a 

 large basisphenoidal process, and in the possession of a distinct tabular 

 bone. It is degenerate and specialized in the rudimentary condition of 

 the orbitosphenoid, in the loss of the ectopterygoid interparietal, and 

 jugal, aud the lack of development of a zygomatic process of the 

 squamosal. The examination of the skull confirms the result of the 

 examination of Jacobson's organ and its relations in showing that 

 Chrysochloris is not a near ally of Cenietes, and that it is not an 

 Insectivore. It is not allied to the Menotyphla and requires a distinct 

 order, Chrysochloridea. 



Classification of Reptilia.f — E. S. Goodrich maintains that the 

 group Reptilia represents not a true monophyletic class like the class 

 Mammaha and the class Aves, but rather an assemblage or grade of 

 Amniotes retaining a more primitive general structure. The Reptilia 

 thus include a basal Proto saurian group of amphibian-like forms lead- 

 ing to a central point from which diverge two main branches — the 

 Sauropsidan branch leading to the birds and the Theropsidan branch 

 leading to the Mammals. The modern classification based chiefly on 

 the skull is very uncertain. The development of a hook-shaped fifth 

 metatarsal and of a mesotarsal articulation, and the subdivision of the 

 aortic trunk so as to form two systemic arches crossing at their base 

 in such a way as to become separated by the interventricular septum, 

 clearly distinguish the Sauropsidan from the Theropsidan line of 

 evolution. 



Conspicuous Patterns. J — J. C. Mottram has sought to define 

 experimentally the conditions of conspicuousness, trying plain and 



* Proc. Zool. Soc. London, 1916, pp. 449-59 (1 pL). 



t Proc. Koy. Soc, Series B, Ixxxix. (1916) pp. 261-76 (4 figs.). 



X Proc. Zool. Soc, 1916, pp. 383-419 (20 figs.). 



