DE. T. DAVIDSON ON EECENT BRACHIOPODA. 145 



tljc stomach by two ducts on each side, of which the anterior were the larger. They 

 did not extend over or cover the sides of the intestine." 



[L. c. p. 2jf.] "The licart is extremely small and difficult to find. It is situated lower 

 down than in most species, and between and hidden by the hepatic lobules. It is nearly 

 spherical. No accessory pulsatile vesicles were found, after close scrutiny. 



" The ovaries differ in appearance from those of JFaldhelmia and Terebmlnllna. They 

 hang like a frill or puckered ribbon-like lamina from the pallial membranes, and form a 

 simple loop on each side of each valve. Those of the hgemal (dorsal) valve Avere most 

 developed. The ends of the loops extended into the great pallial sinuses. The rounded 

 granules which studded the frills were of two kinds. Those at or near the extreme edge 

 were of a pellucid deep brown hue, while those closer to the pallial membrane were mostly 

 of a pale yellowish color, and quite opaque. The oviducts are very inconspicuous and 

 not easily found. They are situated in the usual position, but exhibit only a very few 

 short folds, and the external opening directly in the midst of them, instead of being at 

 the end of a rather long duct, as in other forms. There are only two of them. They do 

 not appear to be attached to the intestine or mesenteries, but lie flatly upon the parietes. 

 The pallial sinuses are comparatively insignificant in this species, being very narrow, 

 almost linear, channels with few branches. A few spicula3 were observed in some of them. 

 The margin of the mantle is perfectly plain, without seta3, and adhering closely to the 

 shell. Yet the circumpallial muscular band is m;ich broader than usual, and strongly 

 marked. When torn from the shell, the csecal prolongations of the mantle were beautifully 

 shown. They wei'e often bifurcate and occasionally had three or even four branches. 



" The punctate structure of the shell was very coarse. Even the crura and laminae 

 of the apophyses were punctate. The nervous system was not traced out ; but the 

 oesophageal ganglia presented no special peculiarities. 



"The border of the mantle appeared to be ciliated. The peduncle, so wide and short 

 as to resemble a mere muscvilar disk, was strongly attached to the shell by the peduncular 

 muscle, beside which a broad tendinous band appeared to pass entirely across, in front 

 of the dorsal adjustors (posterior retractors of Owen), giving an additional solidity and 

 firmness to the attachments of the peduncle. The extremities of all the muscles were 

 very much enlarged and thickened, while their median portions were slender and 

 tendinous. No striated fibres were observed." 



82. CiSTELLA Bakrettiaxa, Davidson, sp. (Plate XXIII. figs. 1 & 2.) 



Argiope Bmrettiana, Davidson, Proc. Zool. Soc. 1866, p. 103, pi. xii. fig. .3. 

 Argiope Antillarum, Crosse & Fischer, Journ. de Conch, vol. xiv. p. 270, pi. viii. fig. 7, 1866. 

 Cistella Barrettiana, Dall, Amer. Journ. of Conch, vol. vi. p. 14G, 1870; and Proc. Acad. Nat. Sci. 

 Philadelphia, 1873, p. 193. 

 Cistella [1 Schrammi, var.) ruhrotincta, Dall, Bull. Mus. Comp. Zool. vol. iii. p. 19, pi. i. fig. 6, 1871. 

 Cistella Barrettiana, Davidsou, var. rvbrotincta, Dall, ]\Ioll. 'Blake' Exped., Bull. Mus. Comp. Zoiil. 

 vol. xii. p. 203, 1886. 



Shell small, somewhat subpentagonal, wider than long; dorsal valve semicircular. 



