218 



GEODINELLA llOBUSTA. 



18° E., 1.7 km. (0.9 miles); drift N. 2° W.; depth 75-245 m. (42-134 f.); they 

 grew on a bottom of gravel and sponge spicules; the bottom temperature was 

 8.8° (47.8° F.). The specimen of var. megasterra was trawled at Station 2946 on 

 February 6, 1889, off southern California, in 33° 58' N., 119° 30' 45" W.; depth 

 274 m. (150 f.); it grew on a bottom of coarse gray sand; the bottom tempera- 

 ture was 13.6° (56.5° F.). 



TABLE SHOWING THE VARIETAL DIFFERENCES IN GEODINELLA ROBUSTA. 



Varieties 



carolae 



megaclada 



megasterra 



Shape 



incrustinp;, cushion 

 shaped. 



finger shaped. 



finger shaped. 



Rhabds. 



amphioxes; amphist ron- 



crvlpc ■ n rnT"^ n 1 1 vIpq * 



styles; subtylostyles ; 

 0.37-2.5 mm. long, 40- 

 65 ji thick. 



amphioxes, 1.6-2.8 mm. 

 long, 33-60 /! thick. 



amphioxes, 1.6-2.8 mm. 

 long, 33-60 /X thick. 



Teloclades. 



monaenes and occasion- 

 ally diacnes; rhabdome 

 1.1-L7 mm. long, 26- 

 40 /( thick; clades SO- 

 TO /( long; cladal angles 

 93-130°. 



monaenes only; rhabd- 

 ome 1.4-2 mm. long, 

 25-42 /I thick; clades 

 80-150 n long; cladal 

 angle 85-135°. 



monaenes only; rhabd- 

 ome 1.4-2.1 mm. long, 

 26-40 /( thick; clades 

 30-70 /( long; cladal 

 angles 93-103°. 



Oxyasters and oxy- 

 sphaerasters. 



11-36 /( in diameter; 

 with 6-18 rays; central 

 thickening visually well 

 developed. 



11-30 /( in diameter; 

 with 11-20 rays; cen- 

 tral thickening usually 

 small or absent. 



9-38 /( in diameter ; with 

 6-17 rays; central thick- 

 ening usually small or 

 absent. 



Stiongylosphaerasters. 



7-12 /( in diameter; 

 with 11-27 rays; central 

 thickening 3.5-7 /( in 

 diameter. 



10-12 /( in diameter; 

 with 19-25 rays; cen- 

 tral thickening 5-7 /( 

 in diameter. 



8-13 /( in diameter; with 

 12-19 rays; central 

 thickening 3.5-7 /i in 

 diameter. 



Sterrasters. 



ellipsoidal; 180-195 

 long, 130-160 ji broad, 

 80-115 /(thick. 



ellipsoidal or, more 

 rarely, thrce-lobed ; the 

 ellipsoidal ones 190-217 

 /( long, 160-190 /( broad, 

 105-125 /( thick. 



ellipsoidal or, more 

 rarely, three-lobed; the 

 ellipsoidal ones 220- 

 237 /( long, 165-200 /i 

 broad, 103-120 ii thick. 



In 1898 Thiele (Zoologica, 24, p. 12) described a geodid sponge with reduced 

 and irregularly arranged, partly axially situated teloclades and large ellipsoidal 

 sterrasters from the northwestern Pacific (Japan). As the specimen at his 

 disposal was merely a small fragment, he, although convinced that it did not 

 belong to any of the geocUd genera then known, refrained from establishing a 

 new genus for it, and named it Geodia (?) cylindrica. 



When I was preparing the systematic account of the Tetraxonia for the 



