and remarhaUe North- Atlantic BracMopoda. 251 



two funnel-shaped processes, which divei^e from the beak 

 in the tipper or larger valve, and of two blade-hke piocesses 

 beidesa^pright plate or ' septum in the upper part of the 



^^IS — "W^W^IVonj which^ita^ear^to 

 be distinguishable only by the straight instead of incurved 

 beak, and by the arms or brachial apparatus not bemg coiled. 



Atretia gnomon *, Jeffreys. 



Shell triangularly oval, compressed, thi^ f^^J^^^^^ 

 and rather glossy : sculpture, a very few slight and indistinct 

 WitudSaT ridges, and numerous close-set microscopic im- 

 bricated scales : coZour white: mar^fns broad and rounded in 

 W slophig gradually at the sides, and acute-angled behind : 

 Lai in the upper or larger valve somewhat promment : fora- 

 tt trLnguff and groove-like, narrow, and ^-^^^^^1^^^^, 

 below th? beak (as in Bliynclionella psittacea), a seiies o 

 a? hid septa or laininar marks of growth : %-- ^ f "^^^^ 

 deltidium\d\ defined: hinge-plate ^^^ong: teek m uppei 

 valve two resting on a triangular funnel with its moutli or 

 openhi Jou warc^^ in the lower valve there are also two teeth 

 whth aJL nearly straight, slender, and blade-like :^oc^e^^ 

 deep Zeln co^mposeS of an erect and thin tnangu ar crest 

 orseptum in the middle of the lower va ve, like a sun-dial- 

 sdle wS is pointed at the top, besides the above mentioned 

 procersrin eak valve ; on either side of the septum are two 

 Tght T-dlel ridges which extend from the hmge and a 

 diverging ridge towards the lower end of the septum. L. 25, 



B. 0-2. 



A single living specimen occurred in lat. 63° 9 N., long. 

 56° 43' W., at a depth of 1100 fathoms, clayey mud. It was 

 attached bl the bysius to a fragment of a tubular Forammifer 

 and covered with a cluster of young Atretice in cWerent 

 s ates of growth, and a dwarf form or variety of Tnmca- 

 £ lobLla. Valves aiid fragments were also^o 

 lat 59° 10' N., long. 50° 25' W., and m lat. 5b U IN., 

 W 37° 41' W'., at depths of 1750 and 1450 fathoms. Im- 

 peXrvalves had been Wed b^ me during the ^Porcupine 

 l:xpedition of 1869, in stations 20 and 30 at deptj.s of 144^^^ 

 and 1380 fathoms, off the west coast of Ireland. 1 his curious 

 Braciiopod was noticed and figured by Mr Davidson m his 

 Supplement to the ^ Monograph of the British Fossi Bi;achio- 

 poda' (Publications of the Paleeontographical Society, 1874) 

 p 7 , pi. i. figs. 7-10 ; but the restoration from the impertect 

 * Having a septum like the hand or stile of a sun-dial. 



