T. Davidson — Wliat is a Brachiopod? 
203 
peduncle to various marine objects, and very offen to the outer sur- 
face of one another’s valves, and even quite young individuals to the 
peduncle of the parent shell, as may be seen in a number of speci- 
mens of Terebratidina septentrionalis sent me frorn America by Prof. 
Verrill. I have likewise clusters of Terebratella rubicunda from 
New Zealand, adhering to each otker in a similar manner. They 
occur also in great numbers attacbed by a shorter or longer peduncle 
to coral reefs, and several minute species were found by Dr. Gwyn 
Jeffreys fixed to sea-weeds. Kraussina rubra, from the coast of Natal 
in South Africa, was described by Dr. Gray as found attacbed in vast 
numbers to Ascidia and stems of sea-weeds. We may likewise men- 
tion that a small species of Kraussina has been recently obtained by 
Mr. Yelain (during the Prench expedition to make observations re- 
lative to the transit of Yenus) in the inferior of the breached and 
submerged erater-basin of the Island of St. Paul, attached, in vast 
numbers, to rocks at low tkle-mark, 1 and I am informed by Dr. 
Gwyn Jeffreys that Terebratulina caput- serpentis was found by the 
late Mr. R. T. Loweliviry, nearly forty years ago, in the living 
state, attached to a rock at low-water mark, on a part of the Scottish 
coast where the tide falls only a few feet. The same species occurs 
also at variable depths, having been dredged alive from depths 
varying from three to upwards of 150 fathoms. Waldheimia cranium 
has been obtained from depths varying from 160 to 228 fathoms. 
Dr. Gwyn Jeffreys does not believe that the habitat of any inver- 
tebrate animal is affected by bathymetrical conditions. The late 
Prof. J. Beete Jukes collected any number of Waldheimia flavescens 
or australis while boating in Australia among the reefs ; they were 
merely washed by the tide, and he gathered them with his hand like 
limpets on the shore. , 
Lucas Barrett informs us that this species, as well as Terebratulina 
caput-serpentis, manifested a remarkable power and disposition to 
move on its peduncle, and that the cirri were almost constantly in 
motion, and he offen observed them to convey small particles to the 
channel at their base. Dr. J. Gwyn Jeffreys, who has watched 
Terebratula alive, informs us that they were incessantly opening 
and folding their brachial or labial appendages, and drawing and 
sucking in by means of the Whirlpool thus caused every animalcule 
within their influence. 
Classification . — Having briefly alluded to some of the most im- 
portant characters of the shell and animal of the Brachiopod. it is 
necessary to refer to their Classification. This matter will be found 
fully discussed up to the year 1853 in the general introduction to 
1 Mr. Yelain informs me, that the Brachiopods he forwarded to me (a species of 
Kraussina) are found in great abundance on the shore, in the interior crater of the 
island of St. Paul. During the ordinary low tides they are scarcely covered by water, 
and are alternatelv covered and left bare at the ebb and flow of the tide, but twice 
a month, during the high tides, they are left completely dry. They occur only in an 
area of a few yards, and consequently at a very shallow depth, doubtless Decnuse 
they find there those undisturbed conditions to which they are accustomed in other 
localities. 
