ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 333 



Isodictya palmata (Ellis & Sol.). Shetland (Fleming and Jameson), and more 

 recently in 1864 (fide, Bowerbank). 



infundibuliformis (Linn.). Common on the Haaf in 50-170 fathoms. 



My largest specimen measures 9| inches in diameter across the cup, and 

 is about 6 inches high. 



" laciniosa, Bowerbank, n. sp. Sponge sessile, fan-shaped, thin. Surface 



uneven, laciniose, minutely hispid. Oscula and pores inconspicuous. 

 Dermal membrane pellucid, spiculous ; spicula acuate, long and slender, 

 not very numerous ; retentive spicula dentato-palmate, equianch orate, 

 palm rather exceeding one-third the length of the spiculum, tooth ter- 

 minally truncated, numerous, very minute ; and also bicalcarated biha- 

 mate, hami terminations truncated, numerous, very minute. Skeleton 

 rete very diffuse and open, primary lines with from three to five or six 

 spicula in thickness ; secondary lines irregular, mostly unispiculous, oc- 

 casionally containing two or three spicula. Spicula acuate, stout and 

 large. Internal defensive spicula attenuato-acuate, incipiently spinous, 

 minute, few in number. Interstitial membranes spiculous ; tension and 

 retentive spicula same as those of the dermal membrane. Colour in 

 the dried state light ochreous yellow. Habitat. Shetland, 170 fathoms 

 (J. G. Jeffreys, Esq., and Rev. A. M. Norman). Examined in the dry 

 state." 



The type-specimen is fan-shaped, with several pliciform projections. 

 It measures 7 inches in height and 10 inches across. The structure 

 is so unusually open that the sponge is translucent in every part. It 

 is a large and remarkably elegant species, on account of its open net- 

 like structure. It was dredged 20-25 miles N. by W. of Burrafirth 

 Lighthouse in 1867. 



fucorum (Johnston). Abundant between tide-marks on the side of 



Halse Hellyer, Burrafirth. 



Barleei, Bow. " Haaf Banks, Shetland, Mr. Barlee and Mr. Hum- 

 phreys " (Bowerbank). 



fanbriata, Bow. Abundant in one spot some 40 miles east of Whalsey 



Skerries, 1861, also to the north of Unst, 1868. 



Genus EAPHIODEKMA, Bowerbank, n. g. 



" Skeleton without fibres, composed of an irregular network of polyspi- 

 culous fagot-like bundles, the spicula of which are compactly cemented to- 

 gether at the middle, but are radiating at their terminations." 



" llapliwderma coacervata, Bowerbank, n. sp. Sponge sessile, fan-shaped, 

 thick. Surface even, irregularly areolated. Oscula simple, minute, 

 numerous. Pores inconspicuous. Dermis reticulate ; rete polyspiculous, 

 irregular, very strong and wide. Dermal membrane pellucid, abun- 

 dantly spiculous ; tension-spicula attenuato-acerate, long and very slen- 

 der, dispersed or loosely fasciculated ; retentive spicula contort bihamate, 

 minute and slender, exceedingly numerous, and dentato-palmate equi- 

 anchorate, variable in size, few in number, dispersed or congregated in 

 circular groups. Skeleton irregular and very coarse ; rete polyspiculous ; 

 spicula subfusiformi-acerate, rather stout and long. Interstitial mem- 

 brane spicula same as those of the dermal membrane ; dentato-palmate, 

 variable in size, equally dispersed, largest ones occasionally congregated 

 in circular groups. Gemmules subspherical, membranous, aspiculous. 

 Colour in the dried state cream-white. Habitat. Shetland, 170 fathoms, 

 J. G. Jeffreys, Esq. and Rev. A. M. Norman." (Bowerbank, MS.) 



