Valkeria. ZOOPHYTA. SERTULARIADiE. 551 
ria cus. Linn. Syst. i. 1311. Pall. El. 125. Abild. Zooh Dan. t. cxvii. 
1, 2, 3 — ^Valkeria cus. Flem. Wern. Mem. iv. 485. t. xv. f. 1. — On 
Corallines in deep water. 
Height seldom above two inches ; several stems usually arise from the 
same base, filiform, jointed, waved, and support the branches and cells bifa- 
riously ; branches opposite, nearly perpendicular to the stem, with a joint 
immediately above their insertion ; cells oval, sessile, upwards of 10 times 
the breadth of the stem, in pairs, at remote distances, projecting, and are 
probably ultimately converted into branches ; sometimes they occur in pairs 
or crowds in the axillae of the branches ; polypi extend considerably beyond 
the margin, tentacula with hairs, which, by their motions, cause the ivater to 
ascend in a current on one side, and descend on the other, acting, probably, 
as aerating organs. 
197. V. Uva. — -Stem creeping, irregularly branched, cells 
scattered. 
Grape coralline, Ellis, Cor. 27, t. xv. f. 25. D.-—Sertularia uva, Linn^ 
Syst. i. 1311. — S. acinacea, Pall. El. 123.— -Clytia uva, Lamour. Cox. 
Flex. 203. — On Flustra foliosa. 
Stem creeping, much waved, cells oval. This is a species, the true cha- 
racters of which are involved in considerable obscurity. 
* Stem compound. 
198. V. Stem erect, dichotomously divided, waved ; 
cells on one side. 
Silk coralline, Ellis, Cor. 20. t. xi. f. 17. B.— Sertularia spin. Linn. Syst. 
i. 1312 — S. sericea, Pall. El. 114.— Laomedia spin. Lamour. Cor. Flex. 
208.— On oyster beds. 
Height upwards of a foot ; slender, like silk ; principal stem formed by 
the union of several tubes, dichotomously divided ; subordinate branches al- 
ternate, and dichotomously divided ; the cells seem confined to one side, ra- 
ther distant, oval, sessile. 
Gen. LXXI. CYMODOCIA. — —Stem tubular, annulated 
below, united above, without any internal partitions ; cells 
cylindrical, filiform, alternate or opposite. 
199. C. comata.-—^X.cm erect, branches verticillate and 
waved. 
liammr. Zooph. 15, t. Ixvii. f. 12, 13 — Coast of Devon, Dr Leach. 
Stem straight, cylindrical, slightly divided ; branches capillary, jointed, a 
minute cell at each joint, with a wrinkled base. Structure yet obscure. 
At the close of this group of animals may be noticed the doubtful Sertula^ 
ria pustulosa of Ellis, Cor. 57, t. xxvii. f. B. It is described as jointed, and 
alternately but thinly branched ; towards the upper part of every joint are 
several shallow cells, having a little circular rim with a point in the middle 
of each. Its relations remain to be determined. 
