446 Mr. C. Spence Bate on some Atlantic 



I obtained several species of marine Crustacea while at Rio. 

 In an excursion which I made along the beach outside the 

 harbour, I saw many S2)ecimens of an Ocypoda^ but only suc- 

 ceeded in capturing one, owing to the extreme rapidity of 

 their movements ; and on another occasion I obtained speci- 

 mens of a Lupea^ a Hepatus, and a Hippa^ in Five-fathom 

 Bay. 



In the month of September the screw of the vessel was raised 

 in order to clean it, and I found numbers oiCaprella [App.,VIII.] 

 clustering amongst the tufts of zoophytes with which the 

 metal was profusely covered. I send you specimens of this, as 

 well as of a crustacean * which has occurred in plenty in the 

 towing-net several times in the course of our voyage south- 

 wards to the Strait. We expect to enter the Strait in the com'se 

 of a couple of days, and shall be there and in Smyth's Channel 

 for six or seven months, after which we shall probably spend a 

 few months at Valparaiso. If you have leisure to write me a 

 few lines, it will be doing me a great favour; for I am very much 

 cut off at present, as you may imagine, from scientific intelli- 

 gence. My addi-ess will be " H. M. S. ' Nassau,' Valparaiso, 

 via Panama." 



With kind regards, believe me, 



My dear Sir, 



Very truly yours, 



Robert O. Cunningham. 



Appendix. By C. Spence Bate. 



I. Alima liyalina. — From researches made by Dr. Power 

 during his stay in the Mauritius, and which are now in my 

 hands preparatory to publication, I have great reason to be- 

 lieve that the genus Alima is but the second stage in the de- 

 velopment of the genus Squilla and its allied forms. 



II. Ligia. — No species (that I am aware of) has been re- 

 corded from the eastern coast of South America. It may 

 therefore be L. Baudiana of Milne-Edwards, from the Gulf of 

 Mexico, which bears a very near general resemblance to the 

 British species. The habitat, however, is very remarkable ; 

 for the European species is never found in water, but only 

 within reach of the spray of the sea. 



III. Idotea annulata, Dana (PI. XXI. fig. 1). — The deep 

 blue colour of which Dr. Cunningham speaks appears to be 

 a peculiarity belonging to pelagic species. I have received 

 specimens of this same from Dr.Wallich, who says that it " is 

 a parasite on Physah'a, almost invariably adherent to the 



* Idoica annulata. 



