160 



THE YOUNG 



NATURALIST. 



time individuals of the same species pro- 

 cured in an adult state. 



Such conferva as grows spontaneously in 

 in an aquarium after a lapse of time is un- 

 doubtedly the best, but possibly you will 

 not care to wait for its appearance, and will 

 prefer to introduce a few seaweeds yourself. 

 The common broad green weed (Ulva latis- 

 simi), or the hair-like rock joint-wort {Con- 

 ferva rupestris), or almost any other of the 

 green kinds will do very nicely ; but have 

 nothing to do with the scarlet hair-wort 

 (Dasya coccinea), or indeed any of the red 

 seaweeds, temptingly pretty as they may 

 look. The brown kinds also are open to 

 objection, and you will find it best to con- 

 fine yourself entirely to green ones. Choose 

 such as are attached to flint stones or small 

 fragments of hard rock, and place these last 

 among the pieces of granite and coral you 

 have built up in front of the jar, disposing 

 them so that the seaweed presents a pictur- 

 esque appearance. Three or four pieces of 

 ulvae are quite sufficient, if you crowd them 

 too much they will turn black. 



Having arranged your vase, draw off the 

 water with a glass siphon, and re-fill it to 

 about an inch above the level of the marble 

 slab, with water obtained fresh from the 

 sea, and mark its exact height by pasting 

 strips of paper on the outside of the vase. 

 You must subsequently carefully keep it up 

 to the point marked, by adding distilled or 

 pecfectly clean rain water as occasion re- 

 quires, to compensate for the loss by evapo- 

 ration and consequent increase in its specific 

 gravity, 



I have recommended you to build a jar 

 into your rock-work ; it is a plan I have 

 found answer extremely well. By so doing 

 I have kept my aquaria in good order for 

 years without ever having to change the 

 water. The object is to keep some portion 

 of the latter fluid in darkness, and so pre- 

 vent it turning green, which otherwise it is 

 very apt to do, especially in bright weather. 



A slow circulation will constantly go on 

 between the jar and the rest of the vase, 

 and the water will remain clear in the other 

 part. If, however, the vase be so small that 

 it can be readily moved into a darker place 

 as soon as the water shows any tendency to 

 to become green, the jar may perhaps be 

 dispensed with, but yet whatever be the 

 size of the vase make it an invariable rule 

 so to arrange the rockwork that the greater 

 part of the water is not more than an inch 

 or two inches in depth. 



I have said nothing about the inmates of 

 the marine aquarium, but will give some 

 hints as to their management in a subsequent 

 number. I will merely say here that from 

 practical experience the separation principle 

 is the best, and I advocate having a number 

 of small vases with anemones, sabellse, 

 serpulse, terebellae and such like in one, 

 blennies in another, gobies (Gobius minutus) 

 in a third, hermit crabs in a fourth, shore 

 crabs (Carcinas mcenas) in a fifth, and so on, 

 rather than one large vase with a heterogen- 

 eous assemblage of diverse creatures, most 

 of which are hostile to one another. 



Cidaria Prunata. — I wish to record the 

 capture of a freshly-emerged specimen of 

 this moth on April 6th, 18S4. I boxed the 

 insect from some park palings in the neigh- 

 bourhood of my home in the day-time. It 

 was sitting low down and covered with -■• 

 bramble, and allowed me to capture it easily 

 although the sun was shining. Most au- 

 | thorities give May and June for this insect, 

 hence my reason for recording the capture 

 of such a widely-distributed species. — Wm. 

 P. Ellis, Enfield Chase. 



On May 15th, I took certata (1), fluctuata, 

 abruptaria (i), and Eupithecia vulgata off 

 lamps, but have seen nothing else. In 

 my breeding cage, carpini and lacertula 

 have emerged from pupae. — J. Henderson, 

 Heme Hill, 



