140 DE, T. DAVIDSON ON RECENT BEACHIOPODA. 



occlusor and retractor muscles very large and powerful. Length 1 line, breadth Ij line, 

 depth 1 line. 



Hub. East Shetland, Skye, County Antrim (Gwyn Jeffreys) ; Moray Firth (Dawson) ; 

 Dublin Bay (Walker), Belfast Bay ; Exmouth (Barlee and Clark) ; off Guernsey (where 

 Dr. Leskis found more than 200 specimens on a single stone brought up from a depth of 

 20 fathoms); off Weymouth (Damon) ; Sardinia (Verany) ; Etretat, Normandy ; S.W. coast 

 of Erance, Cape Breton (Landcs), Hendage, Basses-Pyrenees, in 32 to 45 fathoms 

 (P. Eischer). 



Fossil. Kirkoen, near Christiania (Sars) ; Coralline Crag, Sutton (Searles Wood), not 

 abundant. 



Obs. The discovery of this interesting little Brachiopod is due to Mr. Searles Wood, who 

 mentioned it under the name of Terebr^atuJa cistellula in his ' Catalogue of the Crag Mol- 

 lusca ' in 1841, and it was dredged in the living state by Dr. Gwyn Jeffreys seven years 

 later. Eorbes and Hanley give a good description of this shell as found in the recent state 

 in their valuable work on ' British Mollusca.' It is there stated that a few specimens 

 had been found in 40 fathoms of water by Mr. Jeffreys and Mr. Barlee while dredging off 

 Skye ; also in 30 fathoms off Croulin Island, near Skye, by Mr. MacAndrew ; and on the 

 Haaf, or deep-Avater fislung-grounds of Zetland, by Mr. Barlee. Dr. Gwyn Jeffreys 

 observes, in his ' British Conchology,' p. 21, that this shell may be easily distinguished 

 from Argiope iieapolitana " in being only half the size and more convex, in the foramen 

 being much larger, and in the inside margin of the upper valve being slightly and closely 

 crenulated, instead of having rather strong and distant tooth-like notches, which is the 

 case in A. neapolitana.'" 



To this species several malacologists have referred the Terebratula lunifera of Philippi, 

 while others have referred that shell to the Plati/dia anomioides. As much uncei'- 

 tainty prevails about the matter, I have preferred, provisionally, to leave T. lunifera 

 among the doubtful species of Plafi/dia{?). In 1852 I published a figure showing the 

 labial appendages and muscles from a dried specimen, as well as the two-lobed loop. 



79. CiSTELLA WooDTVARDiANA, Davidson, sp. (Plate XXII. figs. 7, 7c.) 



Arg'wpv IJoodwardimin, Davidson, Proc. Zool. Soc. 18G6, p. 103, pi. xii. fig. 4. 



Cistella IJ^oodicardiana, Dall, Amer. Journ. of Conch, vol. vi. p. 146, 1870; and Proc. Acad. Nat. 

 Sci. Philadelphia, 1873, p. 195. 



Shell very small, somewhat pentagonal, indented in front. Dorsal valve semicircular; 

 hinge-line straight, as long as the width of the shell, moderately convex, but divided 

 into two lobes by a deep median sulcus. Ventral valve deeper and more convex than the 

 opposite one, and with a longitudinal groove along the middle ; beak very prominent ; 

 area acutely triangular ; foramen large and incomplete, margined by the umbo of the 

 opposite valve and laterally by small rudimentary deltidial plates. External surface 

 smooth, whitish yellow, with a few red patches arranged in interrupted lines radiating 

 from the beak. The shell is also marked with numerous concentric lines of growth. 

 In the interior of the dorsal valve the loop is two-lobed, adhering to a central sub- 



