36 DK. T. DAVIDSON ON EECENT BRACHIOPODA. 



i;;l•o^A'tb. In the interior of tlie dorsal valve the loop is simple and short, and rendered 

 annular in the adult by the union of the crural processes. Sliell-structure perforated by 

 canals. Brachial appendages united by a membrane and divided into three lobes, the 

 central shorter one spirally coiled. Length 1 inch 7 lines, breadth 1 inch, depth 

 10 lines. 



Hab. Kiister informs us that his types were derived from Western Australia. His 

 figures are not good, and he colours them dark brown; some specimens, it is true, 

 are of livid brown, but those brought back by the ' Challenger ' Expedition were of a 

 yellowish colour. It was dredged abundantly by the ' Challenger ' Expedition in 1874 

 off Moncoeur Island, Bass's Strait, in a depth of 35 to 40 fathoms, sea-bottom mud ; 

 many of the specimens being attached by their peduncle to Fecten, Cardium, Area, 

 spines of Cidaris, stones, &c. A dwarfed form Avas also dredged for the first time by 

 Mr. John Brazier of Sydney, at Old Man's Hat Point, Inner North Head, oft' Port 

 Jackson, N.S.W., near the rocks, in 7 fathoms, bottom of dead broken shells with coarse 

 sand and stones ; also at Sow and Pigs Reef, eastern side, Port Jackson, near the rocks, 

 in 3 fathoms bottom. One example was Ibvmd adhering to a valve of TrUjonia 

 Lamarckii, Gray, and is the only specimen Mr. Brazier ever found on Trigonla. 



Obs. When young T. cancellata is often longitudinally spindle-shaped and oval, but 

 with age shows more of a straight front. Some of the ' Challenger ' specimens have also 

 much exceeded in size those figured by Kilster, G. B. Sowerby, and L. Reeve. Tlicre exists 

 likewise in some exceptional sjoecimens a median depression on the anterior portion of 

 the dorsal valve, commencing at about the middle of the shell and extending to the front. 



19. Terebratulina (Agulhasia) Davidsoni, King. (Plate VII. figs. 1-5.) 



Ar/idhasia Davidsoni , King, Annals & Mag. of Nat. Hist. 4tli scr. vol. vii. p. Ill, pi. xi. figs. 1-7, 1871. 

 Terebratulina Davidsoni, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 180. 



Shell very small, elongated triangular, much longer than wide. Dorsal valve about as 

 wide as long, broadest and slightly rounded anteriorly, more tapering posteriorly, 

 uniformly and moderately convex without fold, lateral sides of umbo gently auriculated. 

 Ventral valve pyramidal, rather deeper or more convex than the dorsal one and Avith a 

 slight mesial depression near the front, beak solid, nearly one third of the length of the 

 valve, tapering to a small incurved point, area in form of an acute isosceles triangle ; 

 deltidium long and narrow, closed except at the cardinal termination by the internal 

 plate, foramen incomplete and notch-shaped, lying close to the umbo of the opposite 

 valve. Surface of valves radiately striated with about twenty small ribs, of which about 

 half the number are shorter ones interpolated between the longer ribs. Loop in dorsal 

 valve short and simple, furnished with long crural spurs. Colour white. Length 3 lines, 

 by 2 in breadth and 1 in dejith. 



Hab. Agulhas bank, South Africa, and obtained from a depth of 45 to 60 fathoms. 



Ols. In 1870 several specimens of this elegant lyre-shaped shell were placed in my 



hands by Mr. G. B. Sowerby, and having sent them to my distinguished friend Prof. W. 



King, he kindly offered to publish a description of the shell under the name of Agidhasia 



Davidsoni. Although possessing characters bearing relation to Terebratulina, Prof. King 



