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SQUIRREL'S TAIL. S. Argentea. Polypidom spiry 

 and waved ; cells alternate, bulging at the base, and 

 sharply pointed at the outer edge of the aperture, the 

 upper half divaricated. Vesicles vasiform. 



Corallina muscosa, alterna vice denticulata, ramulis in cre- 

 berrima capillamenta sparsis, Raii Synop. Stirp., vol. 1, p. 36, 

 no. 16. Squirrel's Tail, Ellis' Coral., 6, no. 4, tab. 2. fig. c. C. 

 Sertularia Argentea, Ellis and Soiaoder's Zooph., no. 4. 

 p. 38. Turton's Lin., vol. 4, p. 667. Stewart's Elem., vol. 2, 

 p. 442. Templeton in Mag. Nat. Hist., vol. 9, p. 468. 

 Johnston's Brit. Zooph., p. 134, pi. xii. and pi. xi., fig. 3, 3. 

 Dynamena Argentea, Fleming's Brit. An., p. 544. Sertu- 

 laria Argentea, Lamouroux's Cor. Flex., p. 192. 



Hab. On stones and shells from deep water off Polperro, 

 common ; St. Ives bay. 



Since writing the paper On the Zoophytes of Cornwall for 

 the Polytechnic Society, I have found this species to be more 

 common in deep water than I had previously supposed. In 

 the adult state it is the most beautiful of all our corallines. 

 The stem is smooth, without cells, divided at irregular 

 intervals by imperfect septa, and grows to the height of 

 eighteen inches. The pinnse, which bear the cells, arise in 

 pairs from each internode in such a manner that five or six 

 encircle the stem; and as each pinna is again branched in an 

 irregular, though somewhat dichotomous manner, the whole 

 forms so bushy an appearence, as entirely to hide the stem 

 from view, from which circumstance it derives its name. 

 The polypidom sometimes consists of a single stem only, but 

 at others it has one or more branches of the same size and 

 character as the primary trunk, which greatly adds to the 

 beauty of the species. On our shores, however, the larger 

 specimens are generally much injured from the violence of 

 the waves ; having their ceils and pinnae broken or washed 

 off. The cells are biserial, alternate, bulging at the base 

 with diverging and contracted necks ; their apertures are but 

 slightly everted, being rather directed upwards and laterally 

 than outwards. In some specimens the outer edge of the 

 mouth is produced into a sharp point, which in many others 

 is wanting, the apertures being altogether plain. The vesi- 

 cles arise along the upper edges of the pinuos, and are 

 vasiform, inclining to the ovoid, smooth, and transparent 

 when living, semi-opaque and transversely wrinkled, when 

 preserved. 



Young specimens are very common in deep water, at from 

 one to seven or eight leagues from land, but in form they bear 

 no resemblance to the old. They are simply pinnated in an 



