EEPORT ON THE BRACHIOPODA. 29 



is described by both those malaeologists as differing from that of Terehratula vitrea. 

 Mr Dall observes that " The crura are short and blunt, that the interior part of the loop 

 is characteristic and peculiar (PL II. fig. 10, d). It is strongly squarely convex in the 

 middle, a deep narrow gutter extends on each side of this convexity, and is produced at 

 each side into a point ; between these points and the median convexity, on each side, is 

 a deep slit or fissure ; the anterior end of the convexity is much produced at each side 

 into a point." The animal has also been minutely described by Mr Dall, and after an 

 examination of one of the Challenger specimens, I am able to completely confirm his state- 

 ment. The mantle in the dorsal valve of one of the specimens, showed in a very distinct 

 and beautiful manner the four principal pallial sinuses (PI. II. fig. 10, a), which again 

 bifurcate as they approach the front or margin of the shell, the bifurcated extremities 

 bifurcating before reaching the margin. Mr Dall is, I think, right in maintaining by a 

 comparison of both the external and internal characters that Terehratula vitrea and Tere- 

 hratida cuhensis are distinct species. One of the specimens obtained by the Challenger 

 was quite adult, and attached to a coral. 



Terehratula vitrea, var. minor, Philippi (PI. II. figs. 5, 6). 



Terebratula vitrea, var. minor, PliO., Moll. Sicilire, vol. i. p. 99, pi. vi. fig. 8, 1836. 



Terehratula affinis, Calcara, 1845. 



Tereh-atula minor, E. Suess, tJber die Wohnsitze der Brachiopoden, 1859. 



Shell elongated, oval or ovate, slightly subpentagonal, moderately globose, thin, semi- 

 transparent, glassy, white, smooth. Dorsal valve moderately and uniformly convex, 

 somewhat flattened along the middle. Front-line very slightly convex ; ventral valve 

 convex and a little deeper than the dorsal one, slightly flattened from about the middle 

 of the shell to the front. Beak moderately incurved and truncated by a small circular 

 foramen separated from the hinge-line by a narrow deltidium. Loop simple, short, and 

 small. Shell structure perforated by minute canals. Length 15, width 13, depth 8 mm. 



Habitat. — Two specimens without the animal, were dredged by the Challenger 

 Expedition off the Cape of Good Hope, at Station 142, December 18, 1873, lat. 35° 4' S., 

 long. 18° 37' E., at a depth of 150 fathoms. Bottom temperatm-e, 8°-3 C. Sea bottom, sand. 

 Many examples of Terehratulina caput-serpentis, var. septentrionalis, and large and fine 

 Specimens of Kraussina pisum were obtained at the same time. Another dead shell of 

 Terehratula minor was trawled on March 25, 1873, off Culebra Island, West Indies, at 

 Station 24, in a depth of 390 fathoms, sea bottom, mud, and not far from^ the spot where 

 Terehratidina ivyvillii occurred. Several fragments of the var. minor, and one nearly 

 perfect small dead shell was dredged on June 30, 1873, at Station 73, lat. 38° 30' N., 

 long. 31° 14'W., close to the Azores, atadepth of 1000 fathoms. Bottom temperature, 3°-7C. 

 Sea bottom, globigerina ooze. These last, however, were in a very fragmentary condition, 



