GEODIA AGASSIZII. 

 DIMENSIONS OF ANATRIAENES OF GEODIA AGASSIZII. 



129 



Station 



2886 



2887 



2978 



3088 



3168 



4193 



4199 



4228 



4551 



From 

 all Sta- 

 tions 



4228 



Rhabd- 

 ome 



length 



of apparent- 

 ly full-grown 

 spicules, mm. 





5.3-9 



4 1- 



5.8 



7 2- 

 7 5 



6- 

 7,5 







4-8.2 



4 6 



4-9 





average of the 

 three longest, 

 mm. 





8.7 



5 4 



7 3 



7 







6 



4 6 



6 5 





thick- 

 ness 



of apparent- 

 ly full-grown 

 spicules, n 



10- 

 50 



17- 

 35 



17- 

 35 



20- 

 32 



22— 

 36 



25- 

 33 



20- 

 40 



30- 

 37 



22— 

 32 



10- 

 50 



18- 

 27 



average of the 

 three thick- 

 est, fi 



29 



35 



33 



31 



32 



31 



40 



36 



26 



32.56 



25 



Clades 



length 



of apparent- 

 ly full-grown 

 spicules, ;i 



40- 

 95 



70- 

 150 



90- 

 140 



70- 

 115 



75- 

 155 



90- 

 140 



1 00- 

 130 



95- 

 140 



80- 

 140 



40- 

 155 







118 11 



60- 

 110 



average of the 

 three longest, 



f 



67 



133 



140 



98 



145 



123 



120 



130 



107 







95 



angle 



of apparent- 

 ly full-grown 

 spicules, ° 



50- 

 60 



40- 

 65 



33- 

 60 



40- 

 55 



33- 

 53 



32- 

 47 



38- 

 46 



32- 

 51 



40- 

 48 



32- 

 65 



31- 

 45 



average, ° 



55 



49 



43 



46 



44 



43 



42 



44 



46 



45.8 



38 



The anadiaenes (Plate 28, fig. 28; Plate 32, fig. 44) are rare. They have 

 been found only in tlie adult specimens from Station 3168 and the young speci- 

 men from Station 4228, where also anatriaenes with clades of different length 

 are more frequent than in the specimens from the other stations. In shape and 

 size they perfectly resemble those anatriaenes, and I consider them as such 

 anatriaenes, in which the inequality of the clades is carried to the extent of the 

 complete suppression of one of them. 



The irregular anatriaene-derivates differ from the ordinary anatriaenes by 

 one of the three clades being directed upwards. These anatriaene-derivates are 

 rare. I have observed them only in the specimens from Station 4228. 



The large choanosomal oxyasters (Plate 27, figs. 3b, 6-14b; Plate 30, figs, lb, 

 2b, 4, 5, 10b; Plate 32, figs. 4, 6, 7) of the adult specimens have from four to 

 sixteen rays and a small centrum the diameter of which is usually from two to 



