139 



PLATE LV. 



IsODiCTTA DissiMiLis, Bcnvcrbonli. 



Vol. ii, p. 318, ' Mou. Brit. Spongiadie.' 



Fig. 1. — The type-specimen in tlie cabinet of the 

 Rev. A. M. Norman. Natural si/c. 



Fig. 2. — A spiculum, from tlie primarj^ lines of tlie 

 skeleton. X 250 linear. 



Fig. 3. — A spiculum, from the secondary lines of 

 the skeleton. X 250 linear. 



Since the first publication of tliis species I liave 

 received two other specimens ; one from Mr. Win. 

 Thompson, of Weymouth, five inches higli and three 

 broad, and the other from Mr. W. Saville Kent, who 

 dredged it in 1870, off Guernsey ; this specimen is 

 four inches high and three broad. All the specimens 

 agree in having a short pedicel, and in the fan-like 

 disposition of its branches. The external characters 

 of the species appear to be tolerably constant and 

 reliable. 



IsopiCTYA PAUPERA, Bo'iverbank. 



Vol. ii, p. 328, ' Mon. Brit. Spongiadce.' 



Fig. 4. — Represents four of the specimens of the 

 species received from Mrs. Griffiths, of Torquay. 

 Natural size. 



Fig. 6. — One of the minute, bidentate, equi-anch orate, 

 retentive sjaicula, from the dermal membrane. X 530 

 linear. 



Fig. 6. — A skeleton spiculum. X 250 linear. 



Fig. 7. — One of the slender, fusiformi-acerate, tension 

 spicula of the interstitial membranes. X 250 linear. 



IsODiCTTA UNiFOEMis, BoiJjerdan/c. 



Vol. ii, p. 329, ' Mon. Brit. Spongiadas.' 



Fig. 8. — Represents the type-specimen in the 

 cabinet of the Rev. A. M. Norman. Natural size. 



Fig. 9. — One of the tension spicula of the dermal 

 membrane. X 250 linear. 



Fig. 10. — A skeleton spiculum. x 250 linear. 



