JANIA. — MELOUESIA. 107 



II. Jania. Lamour. [Plate 13, D.] 



Frond filiform, aiti ciliated, dichotomous, branched, coated 

 with a calcareous deposit. Fructification, urn-shaped cera- 

 tnidia, formed of the axillary articulation of the uppermost 

 branches (mostly two-horned), pierced at the apex by a 

 minute pore, and containing a tuft of erect, pyriform, trans- 

 versely parted tetraspores. Named from Janira, one of the 

 Nereides. 



1. J. ruhens, Linn. ; articulations of the principal branches 

 and ramuli cylindrical, about four times as long as broad. 

 Harv. Phyc. Brit. t. cclii. 



On the smaller Alg2e between tide-marks. Perennial. Summer. On 

 all parts of the British coast. — From half an inch to 1 — 2 inches high, 

 densely tufted, dichotomous, many times forked, fastigiate, branches either 

 erect or spreading, gradually tapering upwards. Articxdations cylindrical 

 in all parts of the frond, without prominent angles ; those near the base 

 very short, the upper ones gradually longer. Ceramidia subterminal, urn- 

 shaped, with long horns, formed of from two to four articulations. Colour 

 a pale red, with a purplish shade when quite fresh. A common plant on 

 the shores of Europe, and perhaps throughout the temperate Atlantic. 



2. J. corjiicnlata, Linn. ; articulations of the principal di- 

 visions obconical, compressed, their upper angles sharp and 

 prominent ; those of the uppermost ramuli cylindrical, fili- 

 form. Harv. Pliijc. Brit. t. ccxxxiv. 



On smaller Algae between tide-marks. Southern shores of England and 

 Ireland, Jersey. — Forms small dense tufts, 1 — 2 inches high, composed of 

 slender, dichotomous fronds ; branches fastigiate. Articulations of the 

 principal branches 2 — 3 times as long as broad, tapering to the base, en- 

 larged laterally upwards, compressed, their upper angles prolonged into a 

 conical horn. Colour pale red. Known from the last by the different form 

 of the articulations of the principal branches. 



Suborder 2. Nullipore.e. Frond crustaceous or folia- 

 ceous, opake, not articulated. 



in. Melobesia. Lamour. [Plate 14, A.] 



Frond attached or free, either flattened, orbicular, sinuated 

 or irregularly lobed, or cylindrical and branched (never arti- 

 culated), coated with a calcareous deposit. Fructification : 

 conical, sessile cerantidia, scattered over the surface of the 



