-there are on the internal surface of the oofcer 

 lamina a number of smaller ridges. Thisstructuie 

 is well shewn in & specimen of Balanustintinn abu- 

 lum now *-xhibitfd. The basis of the shell is in 

 some species composed of membrane ; in others it 

 is calcareous, and sometimes it consists of two 

 lamiDiie separarpd by septa, in the eamn manner as 

 the walls Thus by additions to the basis round 

 the circumfert-nce. and to the compartments on 

 their lateral margins (that is on the edges of the 

 radii and hIk^) the shell grows in diameter. It is 

 jncrea-ed in height by additions to the basal 

 margins of the comp^irtments. If the structure of 

 the mature cirripode, and the mode in which 

 provision is m>ide for the strength and growth of 

 its beautiful shell form an interesting subject for 

 investigation, its history during its larval stages 

 is no less worthy of examiu'ition. In the 

 earliest or NaupHus st^ge the lirva- resemble 

 "the entomostraca, the whole dorsal surface being 

 covered by a shield, the posterior end of which is, in 

 the secood stage, prolonged into a sharp point. 

 They are furnished with a single eye, and have 

 iihree pairs of swimming leg^ terminated (after 

 the Brsr moults) with long spines or bristles. The 

 first [.'air of l^gs are single, the other two pairs are 

 bran::hed. After the first or second mnult, two 

 pairs of antenoit are successfully developed within 

 transparent sheaths or horns In the second stage 

 an important change has taken pla'^e. The b'dy 

 is enclo-ed in a bivalve shell ; the antennae appear 

 to be aborted, and two fleshy projpctions are de- 

 veloped, which, in the next st-igei, as-^ume the form 

 of prehensile antennae. In the third or pupal stage 

 there is not much change in the external appe-ir- 

 ance. The singleeye which, in the second stage, had 

 begun to be divided, has now become two distinct 

 eyes ; thejprehensile antenriie are fully develnpeo ; 

 and, instead of three pairs of legs, there are now 

 six pairs. The carapace, which is now nearly the 

 shape of a cypris, completely hides the thorax and 

 limbs. The head, bearing the antenna? and organs 

 of sense in front of the mouth.equals in length the 

 posterior part of the body, consisting of thorax 

 and abdomen. The mouth is but rudimentary, so 

 that the larva in this, its last stage, cannot eat, 

 and, as soon as it has foaod a suitable substance, 

 it attaches iti^elf by means of the antennar and 

 undergoes its final metamorphosis. The ant«nna' 

 are furnii-hed with sucking diske, which have the 



power of adhering to a perfectly smooth surface — 

 even to glass. Into the middle part of the disk 

 Mr. Darwin has traced cement ducts from the 

 body of the pupa, and by means of this cement 

 the disks become fastened to the substance to 

 which the creature has attached itself. The 

 antenn&e now becom«*s functionless, but the ducts 

 continue to convey cement to the point of attach- 

 ment, and this process gof's on during the whole 

 lite of the animal The shell of the pupa, 

 the compound eyes, and the integuments 

 of the thorax and legs are moulted, 

 yix pairs of cirri are formed within the six pairs 

 of natatory legs of the pupa and the valves of the 

 capitulum of the mature barnacle are now formed. 

 This description of the larval changes of the Cirri- 

 pediaappliesequallytothe sessile and peduDcalated 

 families— but now an imp'Ttant differnnce mani- 

 fests itself. In the case ot the spssile acorn-sh«-lls, 

 that portion of the head by which the animal had 

 bpcome attached, exoands inte a broad b'isis. 

 While in the pedunculated barnacle it is elongated 

 into a long stalk composed, not of calcareous 

 mntter, but of coriaceous membrane, lin^d with, 

 three layers of muscle's and filled up with a mass 

 of ovarian tubes and the cement ducts already 

 mentioned. How various are the substances to 

 which barnacles attach themselves, and also the 

 large size to which th'-y grow, may be seen in the 

 epf^cimens now shewn. It is well known that 

 ship's bottoms form a favourite surtice tor attach.- 

 m«nte, and that the progress of vess'-U is often 

 impeded by the enormous quantity of barnacles 

 by which they become encrusted. Various sub- 

 stances are applied as a coating to the bulls of 

 ships in order to prevent or check these mischievous 

 animals, but they appear to be almost indifferent 

 as to whether the surface is of wood, iron, paint, 

 or even a vitreous solution — as is proved by the 

 specimen of a group of Lepas anati/era adhering 

 to the smooth surface of a wine b. ttle. Another 

 point worthy of note is the manner in which shells 

 and stones become thickly covered with Balani, all 

 of the same size, and which, in some cases am so 

 crowded that the shells have been abnormally 

 elongated and mis-shapen in the efforts of the 

 motlnscs to keep pace with their neighbours and 

 avoid being smothered in the struggle for existence. 

 The lecture was illustrated with a laige number 

 of specimens. 



SIXTH WINTER MEETING.— JANUARY 24th, 1905. 



"HINTS OX COLLECTING LEPIDOPTEKA."— By Mb. A. U. BATTLEY. 



At the sixth meeting Mr. Battley gave a very Annual Report), we are unable to give a full 



interesting paper on the collection of moths and account of this lecture. We were to have been 



butterfilies, illu-trating his remarks by means of favoured with special notes, the publication of 



specimens and apparatus, etc. We very much which would have been of great practical utility 



le^^ret that owing to the death of Mr. Battley (see to those of our members who collect Lepidoptera. 



