MISCELLANEOUS NOTES. 1171 



is needed. Gravel, in his " Monographie des Cirrhipedes," page 426, states 

 that the rate of growth from the fixation of the larva until the attainment 

 of the normal size of the adult, is approximately 1 mm. a day ; but it is 

 clear from the observation of others both that the rate of growth is not uni- 

 form in different species and under different conditions and that the rate 

 cited by Gruvel is often exceeded. Darwin ( " Monograph on the 

 Oirripedia — Balanidse," page 156, and " Monograph on the Cirripedia- 

 Lepadidse," page 63) quotes some interesting observations of his own and 

 of other observers made in different latitudes and on different species, and 

 a few notes on the subject may be found in the works of other writers : but 

 as regards Indian seas I have been obliged to rely in compiling this note 

 on observations that have come under my own notice. 



As regards Pendunculates from Indian seas, I only know of one precise 

 statement (see " Ilec. Ind. Mus." page 295), which was based on an ob- 

 servation made by Dr. J. Travis Jenkins. A clean buoy was moored off the 

 Madras Coast on February 23rd, 1910, and was lifted on March 3rd of the 

 same year. On it were found numerous specimens of Lepas anserifera and 

 several of Conchoderrna virgatum var. hunteri. The largest of the former 

 measured 8 mm. in capitular length, and of the latter 15 mm. L. anseri- 

 fera is the commonest non-parasitic Pedunculate in the Bay of Bengal and 

 its larvse must swarm off the East Coast of India in February, for every piece 

 of driftwood or other floating substance is rapidly covered at that time of 

 year with young barnacles of the species. Hoek (" Siboga-Expeditie," Mon. 

 xxxia (Cirr. Ped.), p. 2) states that in the Malay Archipelago, in which 

 L. anserifera (a cosmopolitan species) is also common, specimens with a 

 capitular length of 21mm. were found on the keel of the " Siboga " forty 

 days after the bottom had been cleaned, and that, on another occasion, 

 specimens with a capitular length of 25mm. were found one hundred and 

 seven days after cleaning. The larvfe of the genus Lepas do not measure 

 more than l'5mm. in length at the time of fixation, and I think it is legiti- 

 mate to assume that the individuals found on the buoy must have settled 

 on it almost as soon as it was put into the water. 



The specimens of Conclwderma found on the buoy by Dr. Jenkins are the 

 largest examples of the variety to which they belong I have seen. This 

 variety is apparently confined to the Indian Ocean and probably does not 

 attain the same dimensions as the typical form of the species, which is 

 practically cosmopolitan. Darwin states that off the Galapagos Islands 

 certain individuals of the typical form reached a total length of half an 

 inch ica. 11mm.) and became sexually mature in a period of not more than 

 thirty-three days. He gives the length of the larva at the time of fixation 

 as 0*05 inch. 



The rate of growth of the Acorn Barnacles does not seem to be quite 



