PORIFEEA OF THE L.M.B.C. DISTRICT. ^37 



It generally forms small white patches on the rocks, 

 and is easily recognizable. 

 St/candra cillata, Fleming. 



Owing to an oversight Sijcanilra c'diata was not re- 

 corded in the two previous reports as having been found 

 at Hilbre Island. It had been collected there in the 

 summer of 1885 by the members of the Liverpool Marine 

 Biological Committee,* and I have found a few small 

 specimens of it in the same locality in March, 1890. 

 Common in other parts of the district. 



Explanation of the Plates. 



ch. choanosome. m. gastric cavity. 

 cy. cystenchymatous tissue, p. a. pore area. 



d,m, dermal membrane. p.c. " problematic cells." 



e. ectosome. ])(/. pigment cells. 



e.c. exhalent canals. 2>r. prionorrhabds. 



f.c. flagellated chambers. s.c. subdermal cavities. 



i.e. inhalent canals. ^d. layer of scleroblasts (?). 



Plate X. 

 Fig. 1. Vertical section through outer portion of Halisarca 



rid>ra, n. sp., semi-diagrammatic (X 250). 

 Fig. 2. Vertical section through inner portion of Halisarca 



ndjva, n. sp. (X 250). It is doubtful whether 



the parts in figs. 1 and 2, named " i. c," are 



inhalent or exhalent canals. 

 Fig. 3. Axinella mammdlata, n. sp., natural size. 

 Fig. 4. Scleroblasts (?) oi Axinella mammdlata (X 800). 

 Fig. 5. Portion of a longitudinal section through one of 



the papillse of A.vinella mammdlata (X 150). 



Plate XL 

 Fig. 1. Chalina montagtu, Johnston, natural size. 



*W. a. Herdiiian, in ' ' Intioductiuii" to "Fauna of Liverpool Bay," Vol. I. p. 8. 



