XIV SYNOPSIS OF THE SPECIES. , 



13. nodosusj frond compressed, dichotomo-pinnate ; branches strap-shaped, 

 attenuated at the base, remotely toothed and here and there swelling into 

 oblong air-vessels, wider than the frond ; receptacles lateral, ovate, stalked. 

 (Tab. CLVIII.) 



14. Mackaiij cylindrical or compressed, dichotomous; ah'- vessels elliptical, 



solitary ; receptacles lateral, stalked, pendulous, near the base of the dicho- 

 tomous branches. (Tab. LII.) 



15. canaliculars j frond narrow, channelled, without midrib or air-vessels, 

 dichotomous. (Tab. CCXXIX.) 



VI. HIMANTHALIA. 



16. loreaj frond top-shaped ; receptacles repeatedly forked. (Tab. LXXVIII.) 



Order 2. SPOROCHNACEiE. 



VII. DESMARESTIA. 



17. ligulataj flat, obscurely midribbed, repeatedly pinnate; pinnae and pin- 



nula3 opposite, lanceolate. (Tab. CXV.) 



18. aculeataj branches compressed, slender, bi-tri-pinnate ; pinnae and pin- 



nulae alternate, margined with subulate spines. (Tab. XLIX.) 



19. viridis; frond filiform, repeatedly pinnate; pinnae and pinnulae capillary, 



exactly opposite, patent. (Tab. CCCXII.) 



VIII. AKTHROCLADIA. 



20. villosa. (Tab. LXIV.) 



IX. SPOROCHNUS. 



21. pedunculatus j stem undivided ; branches lateral, simple ; receptacles ellip- 



tical. (Tab. LVI.) 



X. CARPOMITRA. 



22. Cabrersej irregularly dichotomous, linear, narrow, flat, midribbed; 

 branches here and there constricted. (Tab. XIV.) 



Order 3. LAMINAKIACE^E. 



XL ALARIA. 



23. esculentaj frond lanceolate; midrib narrow, cylindrical; leaflets linear- 

 oblong or wedge-form. (Tab. LXXIX.) 



XII. LAMINARIA. 



24. digitata; stipe cylindrical or compressed, elongate; lamina deeply cleft 

 into many linear segments. (Tab. CCXXIII.) 



24.* Var. stenophylla, Tab. CCCXXXVIII. 



25. bulbosaj stipes flat, with a wavy margin, twisted at the base, rising 



from a hollow, warted tuber ; frond deeply cleft into linear segments. 

 (Tab. CCXLI.) 

 2G. longicrurisj stipes very long, slender at the base, hollow and inflated 

 in the middle, tapering to the apex ; lamina undivided, membranaceous, 

 oblong. (Tab. CCCXXXIX.) 



