THE BRITISH FOSSIL BRACHIOPODA. 337 



although broken and imperfect, which came up in a single haul off the Shetland." Some 

 species are very abundant on coral-reefs. 



Having in 1879 been requested by Sir Wyville Thomson to undertake the examina- 

 tion, description, and illustration of the Brachiopoda dredged by the celebrated "Chal- 

 lenger" expedition during the years 1873 — 1876. I availed myself of that opportunity 

 to carefully study and examine all the recent forms of the class then known, and I drew 

 up a catalogue of them with indications of the habitats and ranges of depth at which each 

 species had been obtained. 1 From that investigation it resulted that we are acquainted 

 with about some 100 so-termed species and named varieties of the Clistenterata, and of 

 the Tretenterata about thirty-two : of these a list will be found further on. 



The range in depth of one and the same species is often very variable. Thus, for 

 example, as far as our present information will carry us, the Tretenterata {Lingula, &c.) 

 do not appear to have been found at greater depths than from 1360 to 2000 fathoms. 

 Lingula and Glottidia abound in particular spots, and live at about half-tide mark and 

 partly buried in mud, or at depths varying from three or four inches from the surface of 

 the sea to seventeen fathoms. Morse describes a species {Glottidia pgramidata) which 

 he found in vast numbers in a sand shoal at low water : the peduncle, six times the 

 length of the shell, was partly encased in a sand-tube, of which a figure will be found at 

 p. 329 of this Summary. 



The species of these genera are very abundant where they occur. Of one species 

 {Lingula anatina) the " Challenger " Expedition brought home several hundred specimens, 

 all obtained on the beach at Zamboangan ; Philippines, and Mr. Cuming (the great 

 collector of shells), when at Manilla in 1836, after an unusually boisterous typhoon, 

 collected as many as twenty bushels on the shore. They are made use of as articles of 

 food, and Prof. Morse tells me he has eaten them. Discina has been found attached to 

 stones at low-water mark, and at depths not exceeding forty-nine fathoms. One far- 

 spread form, however {Discina atlantica, King), has been dredged at depths ranging 

 from 690 to nearly 2425 fathoms. 2 



1 Davidson, "The Challenger Reports," 'Zoology,' vol. i, part 1, 1880. Prof. Suess published a list 

 of the depths known up to 1859 in a paper entitled " tTber die Wohnsitze der Brachiopoden " (aus den 

 xxxvii mid xxxix Banden d. Wien. Akademie der Wissenschaften besonders abgedruckt, 1859 — 18b*0. 



2 This small shell, not exceeding two lines in length and rather less in hreadth, was obtained for the 

 first time through the soundings and dredgings conducted by Staff-Commander R. Hoskyn, R.N., for 

 purposes in connection with the then proposed telegraphic communication between Ireland and New- 

 foundland in 1862, and since then has been dredged in no less than eight or nine separate and widely- 

 spread localities. It appears to be very abundant in its haunts, and occurs only at very great depths. It 

 has, like all other abyssal forms, a very thin shell, and was obtained by the " Challenger" Expedition at 

 eight stations. Its cirri are of great length, and barbed throughout with spine-like asperities. It was 

 described for the first time by Prof. Dr. W. King, in the ' Proceedings of the Natural History Society of 

 Dublin,' 1868. Sir James Anderson showed me two specimens he had got while fishing up the deep-sea 

 telegraph cable, 2400 fathoms ; and Dr. Gwyn Jeffreys gave me some specimens of the shell which he had 

 dredged on the return voyage of II. M. Ship " Valorous" from Davis Strait. 



