GEODIA ATAXASTRA. 



95 



DIMENSIONS AND CHARACTERS OF THE SPICULES OF THE TWO VARIETIES OF 

 GEODIA ATAXASTRA. 



Spicules. 



var. angustana. 



var. latana. 



Large choanosomal 

 rhabds 



Minute tlermal rhabds 



Orthoplagiotriaenes 



Mesoproelades (nearly 

 all are triaene) 



Large anatriaenes 



Minute dermal ana- 

 clades 



Large oxyasters 



Oxysphaerasters with 

 slender, spined rays 



Oxysphaerasters with 

 stout, smooth rays 



Small strongylosphaer- 

 asters 



Ataxasters 



Acanthtylasters 



Irregular asters (sterr- 

 aster-derivates) 



Sterrasters 



chiefly amphiox, amphistrongyles 

 and styles rare; 1.2-2.8, mostly 

 1.6-1.8 mm. long and 17-43, mostly 

 22-38 // thick. 



nearly all amphiox, styles exceed- 

 ingly rare; 120-200, mostly 160- 

 200 /( long, and 3-5 u thick. 



rhabdome 1.6-2.3, mostly 1.9-2.2 

 mm. long, and at eladome 29-70, 

 mostly 40-60 .« thick; clades 170- 

 290, mostly 230-270 n long; clade- 

 angle 85-116°, average 100.3°. 



rhabdome 1.6-3.4, mostly 2.1-2.8 

 mm. long, and, at eladome, 9-20 /i 

 thick; (longest) clades 44-80 /i long; 

 clade-epirhabd angles 33-48°, average 

 41.3°; epirhabd 33-73, mostly 40-60 

 1' long. 



rhabdome 2.1-3.1 mm. long; at 

 eladome, 3-10 /i thick; (longest) clades 

 17-68, mostly 30-65 /( long; clade- 

 angles 20-42°, average 34°. 



rhabdome 190-340 /i long; at elad- 

 ome, 0.5-2 /( thick; clades 2-6 /i long; 

 clade-angles 33-57°, average 47.6°. 



two-rayed 40-50, three- to .seven- 

 rayed 21-40, eight- to ten-rayed 15- 

 28 /I in diameter. 



8-13 /( in diameter. 



not observed. 



2.6-6 /t in diameter. 



4-7 n in diameter. 



with ten to fourteen rays, 8-16 /< in 

 diameter, very rare. 



not observed. 



65-78 /( long, 

 58-67 II broad, 

 47-57 /< thick. 



chiefly amphiox, but amphistron- 

 gyles and styles relatively much more 

 frequent; 0.6-1.9, mostly 1.2-1.6 

 mm. long, and 12-37 ,u thick. 



chiefly amphiox, but also a fair num- 

 ber of styles; 145-215 /i long, and 

 4-7 /I thick. 



rhabdome 1.3-1.7, mostly 1..5-1.6 

 mm. long, and, at eladome, 30-45, 

 mostly 30-40 /i thick; clades 1.30- 

 220 ,« long; clade-angle 95-111°, 

 average 101°. 



rhabdome 2-2.4 mm. long, and, at 

 eladome, 7-13 ,« thick; longest clades 

 25-58, mostly 32-50 /i long; clade- 

 epirhabd angle 25-58°, average 43.6°; 

 epirhabd 28-50, mostly 34—47 n long. 



rhabdome 2-2.8 mm. long, and, at 

 eladome 7-12 ,» thick; (longest) clades 

 30-55 ft long; clade-angles 41-55°, 

 average 47°. 



not observed. 



three- to seven-rayed 17-28, eight- 

 to eleven-rayed 15-21.5/1 in diameter. 



10-14.4 /( in diameter. 



13 u in diameter, rare. 



3-6.4 fi in diameter. 



5.3-8.3 /I in diameter. 



with four to nine rays, 10-14.5 n in 

 diameter. 



21-50 ,« in diameter. 



55-65 /I long, 

 50-60 n broad, 

 47-50 /£ thick. 



