On the Natural History and Habits of the Common Prawn. 247 



XXII. — Observation on the Natural History and Habits of 

 the Common Prawn, Palsemon serratus. By IIobeet Waring- 

 TON, Esq. 



Havtxg during the years 1852 and 1853 had the opportunity 

 of making some observations on the natural habits and minute 

 characteristics of the common prawn, Palcemon serratus, which 

 I understand are novel, I have been induced to collect the 

 results together and submit them to the readers of this Journal. 



The observations about to be detailed were made in the small 

 tanks or aquaria already described*, in which the balance 

 between the animal and vegetable organisms in a medium of 

 sea water was permanently maint.iined without artificial aeration 

 or disturbance. The materials employed for eifecting this, in 

 the aquax'ium now under consideration, consisted of the Ulva 

 latissima and Enteromorpha as the vegetable members of the circle; 

 several varieties of Actinia, Madrepora, Annelida, and Palcemon, 

 to represent the animal section ; while the functions of the 

 scavengering mollusks were fulfilled by Littorina, Trochus and 

 Purpura. The small tank, containing these several organized 

 members, was constructed of a zinc framing 3 feet in length, 

 one foot in depth and one foot in breadth, having the bottom, 

 ends and back filled with slate, and the front, or part towards 

 the observer, glazed wdth plate-glass, the whole being covered 

 over loosely by a shade partially glazed, so as to impede the eva- 

 poration of the water, exclude as much as possible the soot and 

 dust of the London atmosphere, while, at the same time, a con- 

 tinual change of air could take place. A quantity of rock-work 

 was also introduced, and so arranged that the creatures could 

 readily find a retreat, or screen themselves from the strong influ- 

 ence of the sun^s rays during the day, and from the numbing 

 effects of radiation in a clear night. A short and small shingle 

 beach was also constructed at one extremity of the aquarium, to 

 enable the various denizens to retreat to shallow water whenever 

 they should be so inclined. 



Into this vessel, thus arranged, several individuals of the 

 common prawn were introduced during the months of October 

 and November 1852; they w^ere fed every second or third day 

 with small pieces of either oyster, mussel, cockle, shrimp, and 

 the like, or, when these could not be obtained, wnth softened 

 shreds of raw, lean meat which had been previously dried by 

 exposure to the air in order to preserve it from putrefaction, 



* Transactions of the Chemical Society, as published in their Quarterly 

 Journal, vol. iii. p. 52, 1850; Garden Companion, January 1852; Annals 

 and Mag. Nat. Hist. vol. x. p. 273, and vol. xii. p. 319, 



