70 DH. T. DAVIDSON ON RECENT BEACHIOPODA. 



remaining portion of the animal." p, peduncle; ^ja, point of attachment of peduncle; c<b, 



pallial cfeca ; se, setae. (" Early Stages of TerebratuUna," Mem. Soc. Boston Nat. Hist. vol. ii. 



pi. i. fig. 3.) 

 Fig. 32. A spiculum of TerebratuUna caput-serpentis : highly magnified (after Hancock) . 

 Fig. 33. Portion of the internal surface of the shell of T. cajjut-serpentis , showing the imbricated 



arrangement, and the intei'nal orifices of the vertical perforations arranged in rows : magnified 



100 diameters (after Carpenter). 

 Figs. 34, 34 a. TerebratuUna caput-serpentis : very young, dredged by the ' Travailleiir ' Expedition. Coll. 



of the Marquis de Folin. 

 Figs. 35-37. TerebratuUna caput-serpentis, var. emargmata, Eisso, = var. mediteiTanea, Jeffreys; from 



the Mediterranean Sea; 37, was dredged alive between Pantellai'ia and Sciacca, Sicily. All 



in Davidson Collection, Geol. Dept., British Museum. 

 Figs. 38-40. TerebratuUna caput-serpentis, var. unguicitlata, Carpenter : 38, 39, exterior of shell ; 



40, interior of dorsal valve. Off Vancouver Island. (Davidson Collection, Geol. Dept., 



British Museum.) 

 Figs. 41-42 a. TerebratuUna CaiUeti, Cross e. 41-41 c. From Barbados (Davidson Collection, Geol. 



Dept., British Museum) ; 42, 42 a. Type, after Ci-osse's figure. 

 Figs. 43-52. TerebratuUna septentrionaUs, Couthouy, from off Halifax, Nova Scotia, and Lockport, 



Maine, at different ages (Davidson Collection, Geol. Dept., British Museum). 43, 44. Full- 

 grown individuals. 47. A cluster of specimens attached to one another. 50, 51. Young 



examples. 48. Interior of dorsal valve and loop; 49. Dorsal valve, showing labial appendages. 



52. Portion of shell, magnified. 

 Figs. 53-53 b. TerebratuUna Cumingi, Davidson : type. From China seas. 

 Fig. 54. TerebratuUna abyssicola, Adams and Reeve, sp. : after Reeve's figure. OfE Cape of Good Hope. 



(Davidson Collection, Geol. Dept., British Museum.) 



Plate VI. 



Figs. 1-8 b. TerebratuUna canceUata, Koch, sp. 1-7. Specimens dredged by the ' Challenger ' Expe- 

 dition off Moncoeur Island, Bass Strait, in from 38 to 40 fathoms ; 7. Interior of the dorsal 

 valve, enlarged, showing the labial appendages. 8-8 b. A small dwarfed form, dredged by 

 Mr. J. Brazier at Inner North Head, Port Jackson, N.S.W. (Davidson Collection, Geol. Dept., 

 British Museum.) Specimens 1-7 in Zool. Dept., British Museum. 



Figs. 9-14. TerebratuUna radiata. Reeve, sp. Different forms from the Cape of Good Hope (Davidson 

 Collection, Geol. Dept., British Museum). 12. Specimen showing black colour-markings. 



Figs. 15-17. TerebratuUna t Murrayi, Davidson. 15. Outline of shell, natural size. 15 a,b, enlarged. 

 16. Dorsal valve, with loop magnified. 17. Dorsal valve, showing mantle, enlarged. Dredged 

 by the ' Challenger ' Expedition near Kermadec Island, south of the Fiji Islands, depth 600 

 fathoms. (Zool. Dept., British Museum.) 



Figs. 18-20. TerebratuUna ? tuberata, Jeffreys, sp. From Josephine Bank, 340 to 430 fathoms (Collection 

 of Dr. Gwyn Jeffreys, now in the Smithsonian Institution, Washington, U.S.A.: figures all 

 much enlarged. 19. Interior of the dorsal valve. 



Figs. 21, 22. TerebratuUna ? trigona, Jeffreys, sp. A young and immature shell, dredged by Mr. Saville 

 Kent off the coast of Portugal, at a depth of 501) fathoms (Coll. of Dr. Gwyn Jeffreys, Smith- 

 sonian Institution, Washington, U.S.A.). 22. The shell opened, to show the loop. 



Figs. 23-25 ft. Terebi-atuUna? incerta,Da.\'idson. 23, 24«. Dredged by the ' Challenger ' Expedition in 

 lat. 1° 47' N., long. 24° 26' W. (Zool. Dept., British Museum, and Davidson Collection). 

 25, 25 a. Interior of dorsal valve, with loop, after Dall, magnified 2i diameters ; dredged by 

 the ' Blake' Expedition off Bequea. (Smithsonian Institution, Washington, U.S.A.) 



