NO. 1978. GIANT SPECIES OF THE GENUS LIMA—BARTSCH. 239 



Station 5519, off Point Tagolo Light, Mindanao (lat. 8° 47' 00" N.; 

 long. 123° 31' 15" E.), in 182 fathoms, on globigerina and sand 

 bottom; bottom temperature, 54°.3. Cat. No. 254979, U.S.N.M. 



From the above one sees that Lima (Callolima) rathhuni seems to 

 like a soft mud habitat, ranging in depth from 161 to 226, or an aver- 

 age of 194 fathoms. 



This species is named for Dr. Richard Rathbun. 



LIMA (CALLOLIMA?) BORNEENSIS, new species. 

 Plate 20, figs. 1, 2. 



Shell apparently large, of suboval outhne. Hinge slanting shghtly 

 upward, with the area occupied by the lunule concavely excavated. 

 Pale canary yellow. Outer surface marked by numerous, somewhat . 

 wavy, almost equal and equally spaced radiating riblets, which are a 

 little stronger at the lunule than on the rest of the shell. In addition 

 to these riblets, the surface is marked by concentric lines of growth 

 with stronger ridges at intervals indicating resting stages. The hmge 

 area is shghtly worn which makes it impossible to be positive about the 

 type of resihum. Interior white, edged with a yellowish band. 



This type, a young specimen, Cat. No. 229312, U.S.N.M., differs 

 from the young shells of any of the species we know, and forces us to 

 consider it distinct. It comes from station 5592, off Silungan 

 Island, Borneo Qat. 4° 12' 44" N.; long. 118° 27' 44" E.), in 305 

 fathoms, on green mud bottom; bottom temperature 43° .2. The shell 

 measures: alt. 39.2 mm., lat. 33 mm.; diameter of the single valve 

 8 mm. 



LIMA (ACESTA) VERDENSJS, new species. 

 Plate 20, figs. 5, 6. 



Shell moderately large, irregularly oval; bluish white; sUghtly 

 gaping at the lunule. Outer surface marked by numerous, quite 

 regular and regularly spaced radiating riblets which are stronger on 

 and near the lunule than on the rest of the shell. The early central 

 portion of the disk is almost smooth. In addition to the radial 

 sculpture, the surface is marked with numerous lines of growth, some 

 of which, marking resting stages, are much stronger than the rest. 

 Hinge shghtly curved, ahnost at right angles to the long diameter of 

 the shell, extending very slightly anterior to the beaks. Resihum 

 deeply impressed, wedge shaped. Lunule strongly developed and 

 deeply impressed. Interior bluish white. 



The young type. Cat. No. 249132, U.S.N.M., was dredged at station 

 5119, off Sombrero Island (lat. 13° 45' 05" N.; long. 120° 30' 30" 

 E.), in 394 fathoms, on green mud and sand bottom; bottom tem- 

 perature, 43° .7; density of water at bottom, 1.02468. It measures: 

 alt. 48 mm,, lat. 40.4 mm.; diameter, 21.5. 



