INTRODUCTION. 



J. HE first indication of the Crustacea which presented itself during the late Voyage of 

 H.M.S. Saniarang, occurred on the 10th of June, 1843, as we slowly sailed through 

 the Straits of Sunda, the surface of which being nearly cairn, was swarming with myriads of 

 Stomapodons, such as the transparent Erichthus and Alima, together with several other 

 genera, as Phronima, Nerocila, and Sphceroma. These were swimming apparently in 

 dense masses near the surface, carried bodfly on by the current setting through the Straits, 

 and darting about among themselves. The Nerocila and Sphceroma rapidly revolve in the 

 water and swim in every direction, while Erichthus, Alima, and Phronima propel themselves 

 more steadfly onwards by repeated flexion and extension of the abdomen. 



While the trawl supplied us with specimens of these, the employment of the dredge 

 furnished us with several forms of Podosomatous spider-like Crustaceans, which occur, 

 however, most frequently and in the greatest number among coral barriers surrounding 

 islands, where they are found concealed among the coral branches and in the holes of 

 madrepores. I have also taken them from tubular sponges and even from among the spines 

 of the larger Echinoderms. We found them in large numbers in the Mindoro Sea, in twenty 

 fathoms water and sandy bottom, on which occasion they were found entangled in huge 

 bunches of a species of pinnatiferous keratophyte. Mr. Adam White, in the Proceedings 

 of the Zoological Society, has described two new species of the genus Nymphon obtained in 

 this manner, under the names of Nymphon Johnsionianum and Nymphon Phasma. 1 These 

 Crustaceans are very slow and languid in their progression, moving their slender articulations 

 but feebly. In the Straits, we likewise obtained by the dredge several fine specimens of the 



1 Ann. and Mag. Nat. Hist., 2nd Ser. vol. i. p. 227. 

 a 



