Halichondeia. ZOOPHYTA. SPONGIAD^. 523 



Tubes smooth on the surface, their walls thick at the base, becoming thin 

 as paper towards the orifice, and internally porous — Montagu refers this spe- 

 cies to the Spongia tubulosa of Ellis's Zooph. 188. t. Iviii. f. 7, which differs 

 in the presence of lateral tubes and firm elastic reticulations on the surface. 



105. H. ramosa. — Soft, tough, erect branches, round or 

 compressed, separate or confluent; with short double-pointed 

 spicula. 



Spongia ramosa, Ray^ Syn. Stirp. 29. Ellis, Coral. 80. t. xxxii. f./. F. 

 Phil. Trans. 1765, t. x. f. B. C. t. xi. f. 1 — S. oculata, Pallas's £1. 390. 

 — S. oc. and dichotoma, Linn. Syst. i. 1298. — S. oc. dich. and stuposa, 



Sol. Ellis's Zooph. 184. Mont. Wem. Mem. ii. 78. t. iii. iv. vi 



Hanging from the under surface of rocks about the low-water mark 

 of spring tides. 



The mode of drying determines the degree of softness of this species ; the 

 orifices are generally disposed on one side of the branches; there arise from 

 a single stem, about a quarter of an inch in diameter, dichotoniously divided 

 branches ; the arms long or short, round or compressed ; sometimes the 

 branches assume a fan shape, the spaces become filled up, and the whole ap- 

 pears pahnate, with proliferous edges ; the height seldom reaches a foot.— . 

 Instead of adopting these different forms, which are often connected with 

 the same stem, as distinct species, as has been generally done by modem 

 authors, I have preferred following Hay, in viewing them as varieties. 



106. H. pdlmata. — Hard, tough, erect branches, with nu- 

 merous raised orifices on the one side ; spicula short, double 

 pointed. 



Spongia pal. Sol. Ellis's Zooph. 189. t. Iviii. f. 6. Mont. Wern. Mem. 

 ii. 80. — In deep water on different parts of the coast from Devon to 

 Zetland. 

 The stem rises from a spreading woody root, and is about an inch in thick- 

 ness, it is irregularly branched, compressed, subpalmated, and upwards of a 

 foot in height ; the fibres have a centro-peripheral and distal direction ; the 

 pores are numerous, unequal, and angular ; the orifices are confined to one 

 surface, with the margins but little elevated. — This species is coarser in the 

 texture, branches less regular, and inhabits deeper water, than the preced- 

 ing, to which it is nearly related. 



107. H. vejitilabra. — Widely funnel-shaped or foliaceous, 

 with woody veins ; rough and brittle when dry ; spicula long, 

 linear and pointed. 



Sea-Ean Sponge, Ellis, Phil. Trans. 1765, 289. t. xi. f. H.— S. ventila- 

 bra, Linn. Syst. i. 1 296. — S. ventilabra and Zetlandica, Jameson, 

 Wern. Mem. i. 561 — S. vent, and sypha, Mont.\Wern. Mem. ii. 105. 

 t. XV. f. i — In deep water on the Scottish coast ; in Zetland termed 

 Ling-hoods. 

 This sponge is extremely variable in form, forming an entire cup, becom- 

 ing shallower with age, of upwards of a foot in diameter ; or with a cup divid- 

 ed into irregular lobes at the margin, or split, and exhibiting a fan-shaped 

 leaf; the base, by which it adheres to stones, is solid, and the stem is very 

 short; the substance is thick at the base, becoming thinner towards the 

 margin ; when old, the central part thickens, becomes reticular, with a brit- 

 tle exterior covering, which may be rubbed off, leaving a skeleton not unlike 

 some Gorgonia ; the pores are of various sizes, those on the inside of the cup 

 or leaf are larger and less angular than the external ones ; the spicula are 

 numerous, and much matted ; the gelatinous matter abounds in the young 



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