DESCRIPTION OF PLATES XXVII. TO XXXVIII. 



The figures on Plate XXVII. are reproduced from photographs made by the Author ; the rest of the 

 figures are reproductions of drawings made by the Author with the Abbe drawing apparatus. All the 

 figures are reduced from these drawings, most of them to two-fifths of the size of the originals ; the 

 final magnification is marked on each figure. 



The letters on the Spicule drawings correspond with those used in the text to indicate the different 

 sorts of spicules. 



X.B. Hair spicules, which occur in many of the sponges, are not shown in the figures. 



The significance of the letters on the other drawings is given in the following list : 



ost. Ostia. 



pros. Prosopyles. 



tip. Apopyles. 



/'. Ports. 



/. ch. Incurrent chambers. 



/. en. canals. 



e. ch. Excurrent chambers. 



e. i'ii. canals. 



osc. Oscule. 



osc. c. Oscular collar. 



osc. e. edge. 



g. c. Gastral cavity. 



<7. Dennis. 



ff. ch. Flagellated chamber. 



or. Ovum. 



sp. Spicule. 



a. r. Apical ray. 



LIST OF FIGURES. 



1. 



2. 



:-!. 



4. 



5. 



(>. 

 7-8. 



9. 



10-11. 

 12-13. 

 14-1 5. 

 16-27. 

 L'*-32. 

 33-34. 



35- 4 (.. 

 41-43. 



Dermafreton hmlgsoni. 



fftreptoconus 

 Achramorpha grandinis. 

 Dermatreton chartaceum. 

 Leucandra frigida. 

 Achramorpha nivalis. 

 Ten-threnodes seotti. 

 Hypodictyon longstaffi. 

 Leueosolenia discovery!. 

 minchini. 



Te/it/trenodes seotti. 



(intnrcticus. 



Li'iii-d/iilrn [iriniigenia var. 



tor aphis. 



Leitrniii/rn frigiila. 

 brumal is. 



44-53. 



54-66. 



57-58. 



59-64. 



(55-74. 



75-80. 



81-97. 



98-1 Oi'. 



103-104. 



105-112. 



113. 



114. 



115-119. 

 120-124. 

 125-130. 

 131-136. 

 137. 



Leucandra grlatinosa. 

 cirrata. 

 hiberna. 

 Dermiitri'tou rhartateum. 



hodgsoni. 

 Streptocon us austral is. 

 Hypodictyon longstaffi. 

 Achramorpha glaeialis. 



grand! nis. 



nivalis. 



Grantiopsis eylindrica. 

 Megapogon cruciferus. 



villosus. 



raripilus. 



pollitaris. 



crispatiis. 

 S//con tenellum. 



