MUSEUM OF COMPARATIVE ZOOLOGY. 147 



position to the anterior two-thirds of the same. No separate arrange- 

 ment for ectoturbinals appears to exist. On the nasal surface the endo- 

 turbinals are, with the exception of the first, without lobes, and the 

 nasoturbinal and the ectoturbinals are absent. The sphenoturbinal is 

 united to the septum by three distinct laminae. 



In the cat * the nasal surfaces are much compressed medio-laterally. 

 With the exercise of a little care, the parts can be analyzed without re- 

 sorting to a transverse section. The first ectoturbinal is excessively 

 short, and presents biconvolute folia directed upward. The second, 

 third, and fourth ectoturbinals are slight, and are biconvolute their 

 entire length. The plates and the convexities of the convolutions are 

 distinctly visible on the lateral surface of the ethmoturbinal mass. The 

 nasoturbinal is biconvolute, the median convolution being the larger 

 anteriorly. The lobule of this turbinal is in height equal to one half 

 the length of the nasoturbinal, and is crescentic in outline. The naso- 

 turbinal and all the ectoturbinals are united anteriorly by a transverse 

 lamina. 



The endoturbinal plates are five in number. The first is the largest 

 of the series. It is obscurely convolute, while the lobule is as long as 

 the plate. It is obliquely placed from above downward, and before back- 

 ward, lying in front of the second and third endoturbinals, and composed 

 of a number of closely-set convolutions. It is the anterior division of 

 Strauss-Durckheim. The second plate also possesses a distinct foliated 

 lobe. The second and third plates are united on the lateral .surface by 

 a common lamina. The third plate is small, concealed from the median 

 surface, without lobes, and partly concealed on the lateral surface by the 

 above-named lamina. The fourth plate closely resembles the second. Its 

 lobule is nearly the length of the plate. The fifth is without a lobe, and 

 convolute medianly, the convex surface of this convolution appearing for 

 its entire length on the free median surface of the ethmoturbinal m 



In the seal, Phoca vitulina (Plate IV. figs. 3-5), the encranial surface 

 presents a narrow septoturbinal surface. It lies on the same plane witli 

 that of the turbinal surfaces, extends over less than one thin! the width 

 of the encranial surface, and terminates anteriorly by an enormous 

 foramen. The rounded surface answering to the ectoturbinal space is 

 bordered by an elliptical row of foramina. The ridgea for the endoturbi 

 Dais are inconspicuous and short, not extending, even for the first endo- 

 turbinal, more than one third of the diameter of the cribriform plate. 



* Elaborate figures of the ethmoid of the eat are contained in tin- work 

 Durckheim, lor. a'/. 



