90 Dr. C. Collingwood on the Distribution of Species of 
reason, as stigmata. This opinion is still maintained by several 
recent observers, especially Leydig* and Meadef. As regards 
Tulk, there is nothing in his well-known memoir { differing 
essentially from the opinion of Treviranus§. 
XIV.— Observations on the Distribution of some Species RA 
Nudibranchiate Mollusca in the China Sea. By Dr. C. 
CoLLinewoop, F.L.S. 
In my rambles upon numerous beaches on the coast of China, 
Formosa, Labuan, Singapore, &c., I always kept my eyes 
open for the species of these often beautiful animals; and being 
tolerably well acquainted with their habitats and the character 
of the most likely localities for meeting with them, I was in 
hopes of making a large collection of perhaps new species 
from these seas. In point, however, of the number of species 
that rewarded my search I was disappointed, and not a little 
surprised at the paucity of individuals and the rarity of 
species. I expected to find such animals in abundance 
upon tropical shores; whereas, although day after day I 
have searched for them, it has been only now and then that 
I have been rewarded by finding one. ‘The shores of these 
regions, so far as I have had opportunity of examining them, 
are less fertile in species than those of our own country ; and 
whether this arises from the season of the year at which m 
examination has been made, or from local circumstances, t 
* “Zum feineren Bau der Arthropoden,” Miiller’s Archiv, 1855, p. 433. 
+ “Monograph on the British Species of Phalangiide,” Ann. & Mag. 
Nat. Hist. ser. 2. vol. xv. p. 395. 
t “On the Anatomy of Phalangium Opilio,” Annals of Natural His- 
tory, ser. 1. vol. xii. p. 153. | 
§ I may be permitted to notice here a matter somewhat beside the 
Beane question. In the same volume of the ‘Annals and Magazine of 
atural History’ (ser. 3. vol. xvi.) in which the translation of my memoir 
on the male generative organs of the Phalangiide appeared, there is a 
short notice by Sir John Lubbock, in which he indicates that four years 
reviously, in a memoir published in the ‘Philosophical Transactions,’ he 
fad explained the same subject in a manner essentially agreeing with my 
observations. Mr. Lubbock was kind enough to send me this important 
memoir (Notes on the Generative Organs of the Annulosa, /. c. 1861, 
p- 610), which had been overlooked by me ; and from it I certainly per- 
ceive that Lubbock is perfectly justified in claiming the priority with 
respect to the correct interpretation of the previously misunderstood 
_ testis and the proof of its connexion with the vas deferens through the 
two canals which I indicated in my paper as vasa efferentia. The same 
memoir also contains some indications of the structure of the accessory 
sexual glands, in the cells of which, I may remark in passing, I have 
lately met with a vacuoliform cavity besides the nucleus, 
