REPORT OjST THE FORAMINIFERA. 
633 
Spirillina decorata, n. sp. (Pl. LX X X V. figs. 22-25). 
Test free, cliscoidal, bilaterally symmetrical, or nearly so ; composed of six or eight 
convolutions of a somewhat embracing tube. Lateral faces slightly concave, peripheral 
edge thin and subcarinate ; perforations obscure in thick-walled specimens, the surfaces 
of which become pitted and furrowed ; aperture of the adult test somewhat contracted 
and triangular. Diameter, ^th inch (0 - 84 mm.) or more. 
This form is distinguished from the other species of Spirillina by its thin subcarinate 
periphery. The contour of the test resembles that of Cornuspira carinata. As the 
shell -wall thickens with age, the perforations appear to be gradually filled up, and even- 
tually have the aspect of minute superficial depressions. The surface is often also marked 
with short transverse furrows, especially near the margin of the coils. 
Spirillina decorata affects deeper water than most of its congeners. It has been 
observed at three points in the North Atlantic, — off the Azores, 1000 fathoms; off the 
Canaries, 1125 fathoms ; and off Culebra Island, 390 fathoms : at one point in the South 
Atlantic, — off Pernambuco, 675 fathoms: and at three in the South Pacific, — off Raine 
Island, 155 fathoms ; off Booby Island, 6 fathoms ; and off Kandavu, 610 fathoms. 
Sub-family 2. Rotalinee. 
Patellina, Williamson. 
Madreporites , Blumenbach [1805], ( fide Bronn). 
Orbulites, pars, Lamarck [1816], Lamouroux. 
Orbitolites, pars, Defrance [1826]. 
Cyclolina, pars, d’Orbigny [1846]. 
Orbitolina, d’Orbigny [1852], Bronn, dArchiae, Gras, Parker and Jones, Carter. 
Patellina, 'Williamson [1858], Carpenter, Parker and Jones, Brady, Alcock, Parfitt, G. M. Dawson, 
Miller and Yanden Broeck, Robertson, Schulze, Terquetn, Siddall, Berthelin, Slione, Wright, 
Fritsch. 
Comdites, Carter [1861]. 
Broadly speaking, the genus Patellina is characterised by a conical or plano-convex test, 
consisting of an external or “ cortical ” layer of annular, semiannular, or spirally-arranged 
chambers, and a central enclosed portion or cavity, occupied either by a deposit of clear 
shell-substance or by a mass of minute chambers, more or less regularly disposed. The 
chambers of the outer layer are, as a rule, subdivided into chamberlets, the secondary 
septa being marked externally by transverse lines. Some of the small and imperfectly 
developed varieties have undivided chambers, either annular or spiral ; and in certain 
