130 DR. C. I. FOESTTH MA.TOR ON THE [Feb. 19, 



d'autres termes, qu'il n'y a pas d os planum, ce qui continue 

 dans les carnassiers et les autres mammiferes, [a un tres petit 

 nombre d'exceptions pres ; mais il existe encore dans les autres 

 lemuriens] " ^ 



The addition in brackets is from the pen of F. Cuvier, one of 

 the editors of the second edition of the ' Leeons ' ^-. 



Kosthn refers to the planum of Lemurs in the following 

 sentence : — " Der TJebergang zu den Halbaffen geschieht (daher) 

 viel deutlicher von den Affen der alten, als von denen der 

 neuen Welt, und es gehort hieher vor alien Stenops^ bei welchem 

 das Os planum in einem langlichen Ausschnitt des Stirnbeins 

 liegt, und nur am untern Eande von diesem frei ist ; ein ahnliches, 

 niedres Os planum scheint Galayo zu besitzen ; dagegen f ehlt es 

 entschieden bei Lemur, Lklianotus, Clieiromys und w ohl auch bei 

 Tarsius " ^ 



Schroder van der Kolk and Vrolik, referring to Nycticehus 

 tardigmdv.s and If. javanicus, repeat almost textuahv Cuvier's 

 words : — " L'ethmoi'de tout entier est enveloppe par le frontal et 

 par le palatin, en sorte qu'il n'en parait rien dans I'orbite ou, 

 par consequent, il n'y a pas d'os planum " *. 



Flower says of the os planum of Monkeys : — " The os planum 

 of the ethmoturbinals always forms part of the inner wall of the 

 orbit, having the same relations as in Man " \ And with regard 

 to the Lemurs : — " In the Common Lemur . . . the os planum of 

 the ethmoturbinal does not enter into the inner wall of the orbit, 

 but is shut out from it by the maxilla, as in most inferior Mammals 

 .... Some of the Lemurina have much shorter faces than the 

 common species, though still possessing all the essential characters 

 of: the group " ^ 



We therefore see that the writers generally deny the presence 

 of an os planum to the Lemurs, of which the genus Lemur is con- 

 sidered to be the prototype, and it has been taken for granted 

 that the conditions found in this genus are those of the whole 

 group. Kostlin is the only writer who gives some positive and 

 on the whole fairly correct information on this point. 



As a matter of fact, all the species of non-Malagasy genera, 

 viz., Tarsius (text-fig. 35, p. 138), Nycticehus (text-fig. 41, p. 140), 

 Loris (text-figs. 40, 42, p. 140), Perodicticus (text-figs. 31-33, 



1 G. Cuvier, Le9ons d'Anat. Comp. 2= ed. t. ii. p. 319 (1837). 



^ It is difficult to understand what is meant here by " les autres lemuriens." 

 Tarsius is out of the question, it being expressly stated that in the only speci- 

 men available all the sutures were obliterated. By " les loris" both Nycticehus 

 and Loris are designated. Chiromys is placed among the Eodents. The only 

 other Lemurs mentioned in the work are the "Indri" axiA AvaMs,m both 

 of which the os planum is united with the palatal at a very early date. 



3 O. Kostlin, ' Der Bau des knochernen Kopfes in den vier Klassen der 

 Wirbelthiere,' p. 93 (1844). 



* T. L. 0. Scbroeder van der Kolk et W. Vrolik, " Eecherches d'Anatomie 

 compar^e sur le genre Sfenops d'llliger," in Bijdragen tot de Dierkunde, 

 uitgegeven door het G-enootschap Natura Artis Magistra, i. 2, p. 39 (1851). 



5 W. H. Flower, 'An Introduction to the Osteology of the Mammalia,' 

 3rd ed. p. 161 (1885). 



6 Op. cit. p. 166. 



