068 EXPLANATION OF TTTE PLATES. 



[D' shows the naked calcareous axis of one of its branches.] 

 D". Portion of 1)', x 6. From Tort MoUe. 



Fig. E. Acabaria serrata. Portion of larger specimen in spirit, nat. 

 size. E'. Portion of second joint above first bifurcation, 

 of same specimen, from Port Darwin, 7-12 fms., x 6. 



F. Iciligorgia oriental is. Typo specimen, in spirit, reduced to 

 one half nat. size. F'. Portion of left-hand branch, the 

 margin as seen from the side, showing the depressions for 

 the zooids and the common groove which contains them, 

 X 2. F". Portion of main stem just below bifurcation, 

 from front, showing four exsert zooids. From Torres Straits, 

 10 fms. 



Plate XXXVIII. 



Fig. a. Mopsella clavigera, cortical clavate, a', cortical bifurcate, 

 and a" & «'", Blattkeule spicules, x 100. 



b. Melitodes albitincta, fusiform, and b' , small nodular cortical 



spicules, x 100. 



c. Acabaria serrata, long, and c', short verruca-spicules ; c", 



short, and c" , long cortical fusiform spicules. All x 150. 



d. Ecliinomuricea indo-malaccensis. d & d', chief forms of the 



toothed spicule of the verruca, d" & d'", cortical spicules. 

 All x70. 



e. Iciligorgia orientalis. Chief forms of spicules, X 70. 



/. Psilacabaria gracillima, cortical, /' & f", verruca-spicules, 

 X 70. [The ridged cortical spicule has been omitted.] 



g. Plexaura prcelonga, var. typica, radiate, and g ', Blatt- 

 keule cortical spicules, x 70. 



h. Plexaura prcelonga, var. cinerea, Blattkeule cortical spicule, 

 X70. 



SPONGES. 



Plate XXXIX. 



Fig. A. Stelisj)ongus excavatus. Type specimen (dry) from Arafura 

 Sea. Eeduccd to one half nat. size. 



