90 Dr. C. Collingwood on the Distribution of Species of 



reason, as stigmata. This opinion is still maintained by several 

 recent observers, especially Ley dig* and Meade f. 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 of 

 Nadibranchiate MoUusca in the China Sea. By Dr. C. 

 Collingwood, 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 

 sui-prised 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 tlie year at which my 

 examination has been made, or from local circumstances, I 



* " Zum feinereu Bau der Arthropoden," Miiller's Archiv, 1855, p. 433. 



t " IMouograpli on the Britisli Species of Phalaugiidse," Ann. & Mag. 

 Nat. Hist. ser. 2. vol. xv. p. 305. 



X " On the Anatomy of Phcdmiffium Ojnlio" Annals of Natural His- 

 tory, sor. 1. vol. xii. p. 153. 



§ I may be permitted to notice here a matter somewhat beside the 

 present qiiestiou. In the same volume of the ' Amials and Magazine of 

 Natural History' (ser. 3. vol. xvi.) in which the translation of my memoir 

 on the male generative organs of the Phalangiidce appeared, there is a 

 short notice by Sir John Lubbock, in which he indicates that four years 

 previously, in a memoir published in the 'Philosophical Transactions,' he 

 had 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 Aunulosa, /. c. 1861, 

 p. 610), which had been overlooked by me ; and from it I certainly per- 

 ceive that Lubbock is perfectly justiiied in claiming the priority wiih. 

 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 vam cjferentia. The same 

 memoir also contains some indications of the structure of the accessoiy 

 sexual glands, in the cells of which, I may remark in passing, I have 

 lately met with a vacuoliform cavity besides the nucleus. 



