THE YOUNG NATURALIST. 



45 



rowing. The coral polpys cannot exist above 

 iw-watec mark, but during storms fragments are 

 roken off and tossed up, which become cemented 

 >gether and form land. Coral animals cannot 

 \e at a greater depth than 25 or 30 fathoms, but 

 itside an atoll the sea is often 100 fathoms deep 

 id therefore they could not begin to build an 

 loll with the sea and land in the same relation- 

 lip as they are represented in fig. 27. Mr. Dar- 

 1 in, m however, discovered that the land had 

 radually sunk and at such a slow rate that the 

 3ral animals had been able to build up their 

 ructure as fast as the land had sunk. By this 

 leans a fringing reef would in time become a bar- 

 er reef, and a barrier reef would in like manner 

 2come an atoll. There are a few other forms of 

 lis second division, which include the organ-pipe 

 Dral, and those things we sometimes find on the 

 jast known to most people as "dead mens' 

 pgers." In some of them we find the rudiments 

 f a nervous system. 

 The lecture was delivered before the Hudders- 

 ;ld Literary and Scientific Society, November 

 rd, 1879, an d was illustrated by photographs in 

 te oxy-hydrogen lantern, and by numerous speci- 

 .ens from which most of the figures are taken. 



LEPIDOPTERA IN 

 DECEMBER. 



e gave in our first number a list of the Lepi- 

 Dptera that were obtainable in November. Short 

 5 was the list it was much longer than that we 

 ave to give you for the month of December, and 

 'en in this list are some species that we give, 

 uly because we find them in Mr. Merrin's Calen- 

 ar. We have had some correspondence with 

 ference to the supposed occurrence of C. chamo- 

 illce in November, but a reference to our article 

 ill show that we placed it in the list of November 

 secies, because we found it in Mr. Merrin's list 

 >r that month. We expressly stated we had no 

 nowledge of its appearance at that season, and 

 •iked that anyone taking one would write to us, 

 ncl gave our opinion that if a specimen had ever 

 een taken in November it was an abnormal 



appearance. We think it better we should take 

 our monthly list from one already published ana 

 call attention to doubtful records, than depend 

 simply on our own knowledge, which is necessarily 

 limited. 



The December list in Mr. Merrin's Calendar is- 

 as follows : — 



H. pennaria O. dilulata 



P. pilosaria P. populi 



H. rupicapraria , P. Cassinea 



defoliaria P. plumigera 



C. brumata X. rhizolitha H 



boreata 



Of these H. pennaria, H. defoliaria, C. brumata 

 and boreata, <J. dilulata, P. populi, P. cassinea, 

 and P. plumigera y \\-ere in the November list, and 

 nothing more need be said about them now. This 

 only leaves three species, two of which do not 

 occur earlier than January so far as we know, and 

 the third we think is a mistake. If any of our 

 correspondents can send in a record of the capture 

 of any of them this month we shall be glad to 

 publish it, and thus settle the matter. The species- 

 are Phigalia pilosaria, the Pale Brindled Beauty. 

 It is a common insect in woods and country lanes. 

 We never knew it to appear before January, and 

 it continues to come out during February and 

 March. Mr. Stephens, in his illustrations, gives 

 March as the date of its appearance. It will be 

 fouud on palings or tree trunks, where the per- 

 fectly wingless female may also be obtained. The 

 male flies at dusk and sometimes comes to light. 



. Hybernia rupicapraria, The Early Moth, is 

 sometimes abundant in January, and in a mild 

 winter may have appeared in this month. The 

 female has very narrow short wings, that do not 

 enable her to fly. She may be found on the leaf- 

 less hedges after dark with a lantern. The male 

 comes freely to light, or may be taken on the wing 

 at dusk. During the day it appears to hide more 

 carefully than do many of its congeners. We 

 have found it under old sleepers on a railway bank 

 or on the underside of a fallen tree. It is an 

 insect that seems to bear cold well. 



Xylina rhizolitha, The Grey .Shoulder Knot-, 

 This insect emerges in October or the end of 

 November, and after hybernation appears again in 

 March. We have no doubt it has been placed in 

 the December list in error. It is not an uncommon 

 species in the South, though rarer in the North. 

 It sits on palings or tree trunks through the day. 



