90 Wright— List of Irish Cretaceous Microzoa. 



136. Furcated attenuato-patento-ternate spiculum, PI. II. fig. 18 ; same as the 

 last, but probably from a different species of Sponge. Frequent. 



137. Recurvo-temate spiculum, PI. II. fig. 19 ; similar spicula occur in the 

 intermarginal cavities of Tethea and Geodia, and these are probably from 

 similar positions in the fossil species of these genera. Very rare. 



138. Spiculum, PI. III. fig. I. This form is quite new to me. It is most 

 probably from the expansile dermal system of a siliceo-fibrous Sponge. 

 Rather rare. 



139. Spiculum, PI. III. rigs. 2 and 3. Singular and probably abnormal form 

 of dermal spiculum of a siliceo-fibrous Sponge. Rather rare. 



140. Porrecto-ternate spiculum, PI. II. fig. 20. This form of spiculum occurs 

 in some species of Tethea ( Tethea cranhtm, British). An external defen- 

 sive spiculum. Frequent. 



141. Porrecto-ternate spiculum, PI. II. fig. 21. Very rare. 



142. Porrecto-ternate spiculum, PI. II. fig. 22 ; same as the last, but probably 

 indicating a different species. Rather rare. 



143. Attenuated rectangulate hexradiate spiculum, PL III. figs. 4 and 5, from 

 a siliceo-fibrous Sponge (see "Mon. Brit. Spongiadse," Vol. I. PI. VII. 

 fig. 174). In great profusion. 



SKELETON-FIBRES. 



144. Fragments of skeleton-fibres of a siliceo-fibrous Sponge, PL III. figs. 

 6 and 7. Very rare. 



145. Apparently fragments of skeleton fibre of a siliceo-fibrous Sponge, PL III. 

 figs. 8 and 9. Abundant. 



146. Fragments of skeleton fibre of a siliceo-fibrous Sponge, PL III. fig. 10. 

 Rare. 



