NOTES ON AMPHITRETUS. 



91 



Contrary to the desired result, the reagents have turned the specimen 

 into a shabby object, incomparable to its former beauty. The change 

 consisted in the loss of transparency, in the browning effect of the fixing 

 fluid and in the contraction of parts in general, but especially of the 

 peripheral gelatinous layer. 



This layer is now reduced almost to the condition of an ordinary 

 soft skin. It has shrunk so as to present a wrinkled surface and is no 

 longer of such great moment in influencing the general shape of the 

 animal as it was before. The specimen may now be said to bear a 

 certain resemblance to the figure of Amphitretus pelagicua given by 

 Hotle in the Challenger Keport. 



The head and body together take up nearly one-third of the entire 

 length. They are unnaturally flattened owing to the compression before 

 referred to ; otherwise they would have presented a nearly hemispherical- 

 shape, much like the Challenger specimen. 



The following are measurements taken some time after the pre- 

 servation : — 



Total length 148 mm. 



Breadth of body 45 „ 



End of body to mantle-margin 40 „ 



,, ,, „ ,, the middle point between the eyes. . . 45 ,, 



„ „ „ „ mouth 56 „ 



„ „ „ ,, siphon end 70 „ 



„ ,, ,, the umbrella edge between the 



ventralmost arm-pair 83 ,, 



,, ,, ,, ,, the umbrella edge between the dor- 



salmost arm-pair 115 



Length of arm 86-9G ,, 



Greatest thickness of arm 9 „ 



Diameter of largest sucker at the outer end 21 



It may be observed that our specimen is more than thrice as large 

 as that described by Hoyle. If we are right in referring ours to the 

 same species as his, the latter was probably a young specimen. 



The most characteristic point of the family, viz., the division of the 

 mantle-opening into two separate, right and left apartures, can now be 



