PLATE VII. 



Figure 1. — Leuconia multiformis. 



(a) A gastric quadriradiate spicule, 



(b) A subgastric triradiate spicule, 



(c) A sagittal parenchymal triradiate spicule, 



(d) A young regular parenchymal triradiate spicule, 

 (i ) A dermal triradiate spicule, 



(/) Two minute acerate spicules, 



(;/) A spindle-like large acerate spicule (transverse section) 

 (h ) A young lance-like acerate spicule, 



,, 2. — Leuconia tppica, n. sp. 



(a) A gastric quadriradiate spicule, . 



(b) A parenchymal triradiate spicule, 



(c) A dermal triradiate spicule, 



„ 3. — Leuconia rudifera, n. sp. 



(«-«"') Four minute gastric acerate spicules, 



(b) A gastric quadriradiate spicule, 



(c) A dermal triradiate spicule, 



,, 4. — Leuconia levis, n. sp. 



(a) A gastric quadriradiate spicule, . 



(b) A subgastric quadriradiate spicule, 



(c) A larger parenchymal triradiate spicule, 

 (d-d"') Four smaller parenchymal triradiate spicides, 



,, 5. — Leuconia crucifera, u. sp. 



(a) A gastric quadriradiate spicule, 

 (h) A parenchymal triradiate spicule, 

 (f) A parenchymal quadriradiate spicule, 



(d) A large acerate spicule (transverse section), . 



,, 6. — Leuconia loricata, n. sp. 



(«-«"") Five minute acerate spicules, . 



(b) A dermal triradiate spicule, 



„ 7. — Leuconia dura, n. sp. 



(a-a") Four oscular triradiate spicules, 



„ 8. — Per'tcliurax carteri, n. gen. and sp. 



Ten subdermal spicules in their natural disposition (var. 

 heteroraphis), . . . . 



,, 9. — Leucetta imperfecta, n. sp. 



(a-e) Five minute triradiate spicules, .... 



Diam. 



100 



100 



500 



