BRITISH SPONGIADJ1. 



Sub-section P. Dermal membrane spiculo-reticulated. Skeleton 

 primary lines multispiculous. 



26. Isodictya pallida. 



27. ,, sirnulans. 



28. Ingalli. 



29. Isodictya incerta. 



30. crassa. 



Sub-section G.Spicula of dermis dispersed. Skeleton: primary fibres 



bi- or trispiculous. 



31. Isodictya Bowerbanki (= 



I. simulo). 



32. filamenta. 



33. Isodictya panpercula. 



34. clava. 



Sub-section H. Spicula of dermis dispersed. Skeleton : primary lines 



multispiculous. 



35. Isodictya jugosa. 



36. palmata. 



37. Isodictya trunca. 



Section **. Spicula of the skeleton acuate. 



Sub-section A. Dermal membrane aspiculous. Skeleton : primary 

 fibres multispiculous, smooth. 



38. Isodictya infundibuliformis. 



39. dissimilis. 



40. Isodictya gracilis. 



41. invalida. 



Sub-section B. Dermal membrane spicula dispersed. Primary skeleton 

 fibres with few smooth spicula. 



42. Isodictya Normani. 



43. coriacea (some of the acuates incipiently spinous). 



44. hispida. 



Sub-section C. Dermal membrane spiculous, spicula dispersed. 

 Primary skeleton fibres multispiculous. 



45. Isodictya fucorum. 



53. Isodictya laciniosa. 



