MUSEUM OF COMPARATIVE ZOOLOGY. 137 



another constitutes the transverse lamina. Its posterior portion unites 

 with the vomer, and may receive the name of the turbino-vomerine lamina. 

 Its anterior portion lies in front of the last named. The sphenotur- 

 binals are furnished with olfactory plates that join the vomer, thus 

 crossing the septoturbinal space. 



The surface of the ethmoid bone entering into the construction of the 

 brain case is called the encranial surface. It exhibits a perforate or 

 aibriform plate, and a non-perforate plate placed posteriorly to the fore- 

 going. The perforate plate answers in position to the ectoturbinals, 

 the endoturbinals in great part, and the septoturbinal space. The 

 non-perforate space covers the sphenoturbiuals and the lowest of the 

 endoturbinals. The encranial surface may be subdivided, for con- 

 venience in description, into surfaces which correspond to the divisions 

 of the ethmoid as seen from the nasal chamber. Thus the septo- 

 turbinal, the ectoturbinal, and the endoturbinal surfaces are easily 

 distinguished. 



The Literature of the Ethmoid Bone. — That the terminology of the 

 ethmoid bone at present in use needs revision can be readily shown by 

 a reference to the literature of the subject. 



E. F, Gurlt (Handbuch der Vergleichenden Anatomic der Haus-Saug- 

 thiere, Berlin, 1843, Vol. I. p. 81) describes the ethmoid on the basis of 

 the human bone. He identifies the nasoturbinal as the superior conch 

 and the first endoturbinal as the middle conch. All parts not appearing 

 on the median surfixce he groups under the head of the " Labyrinth." 



H. Strauss-Durckheim (Anatomic Descriptive et Comparative du Chat, 

 Paris, 1845, p. 385) gives the sphenoturbiuals as equivalent to the "cor- 

 net de Bertin," and forming the third division of the bone. The second 

 division is the group of plates seen only in the cat and its congeners. 

 It is a development from the transverse lamina. All the remaining por- 

 tion of the ethmoturbiual, comprising as it does the bulk of the bone, 

 Strauss-Durckheim calls the first or superior division of the bone. The 

 space between the two ethmoturbinals on a level with the lower border 

 of the chamber of the ectoturbinals and the equivalent to the ethmoidal 

 notch of human anatomy receives the name of the " ecartement des 

 anfractuosites superieures." The mesoturbinal is named the " lame ver- 

 ticale moyenne." 



Owen (Archetype and Homologies of the Vertebrate Skeleton, 1848) 

 named the meso-ethmoid the prefrontal, and gave to the ethmoturbinals 

 the name which they have since borne. In his elaborate work on the 

 Anatomy of the Vertebrates, Owen restricts the term ethmoturbinal to 



