274 SERTULARIIDJE. 



PLUMULARIA FALCATA, Lamk. An. s. V. (2nd ed.) ii. 160 ; Johnst. B. Z. 90, 



pi. xxi. figs. 1, 2; Dalyett, An. Scotl. i. 17fi, pi. xxxiii. 

 PENNARIA FALCATA, OJcen, Lehrb. Nat. 94. 



Plate LVIII. 



STEMS slender, flexuous, spirally twisted, destitute of caly- 

 cles; branches alternate, rather distant, regularly pin- 

 nate and plumose, given off above each joint, pinnae 

 alternate, jointed; HYDROTHEC^E tubulous, closely ap- 

 pressed one to the other, ranged in pectinated rows 

 along the pinnse, with a break at each joint, aperture 

 plain and obliquely truncate ; GONOTHEOE ovate, tapering 

 below, with a slightly tubular neck. 



WHEN finely grown this species attains a height of 12 

 inches or upwards ; and the shoots are often compound, 

 dividing, especially towards the bottom, and bearing seve- 

 ral offshoots. The form is singularly elegant, from the 

 spiral disposition of the spreading plume-like branches 

 around the flexuous stem*. The pinnse are jointed at 

 regular intervals ; and each internode bears a company of 

 calycles, Avhich lean, as it were, one upon another, the 

 sharp outer angles of the oblique apertures giving a pecti- 

 nated appearance to the rows ; they occur on the branches 

 as well as the pinnse, but are not present on the main stem. 

 The polypites are minute and pure white. 



The capsules are produced abundantly in spring, and 

 when filled with their yellow ova or planules " resemble so 

 many minute lemons both in shape and colour ." Their 

 structure is simple. A single sporosac, supported on a 

 short peduncle, fills a large portion of the cavity; and within 

 this (in the female) a number of light-yellow ciliated 

 embryos are matured, which escape at once through the 

 terminal aperture without passing through any marsupial 



* " A series of feathers implanted in spiral arrangement around a slender 

 stem." Sir J. Daly ell 



