Pi. cell. aph. 2. THALASSIOPHY TE. 317 
Fam. II. 2. THALASSIOPHYT/. Lamouroux. 
Algarum pars, Linneus and Jussieu. — 
Thallus coriaceous, membranaceous, or fleshy; continuous 
or jointed; fibrous or cellular; sportdza enclosed in thece, 
or immersed in the substance of the thallus.— Plants mostly 
marine, olive green or red, absorbing water by their sur- 
face in the immersed part, but not transmitting it to other 
parts; emit oxygen gas by the action of light. 
A. Thallus jointed, membranaceous, tubular ; joints formed 
of a stmple tube; sporidia enclosed in thece. Ceramidee. 
Thallus olive-green, gelatinous, 
TEGM AGOMMNOM AXIS... 7... so ais'e v's s WLESOGLOTAMZO. 
Thallus green; secondary branches 
simple, bristlelike, swollen at bottom .. BuLBocumreE. 27. 
Thallus brownish ; 
branches jointed; thece naked......... Ecrocarpus. 28. 
Thallus red; knots pellucid ; 
Mee Ge IACAG AN, a. sesciioisisjecovess .... CALLITHAMNION. 29. 
Thallus red; knots coloured ; 
thece involucrated ........:. seeeees se) CERAMIUM. 90- 
_ Thallus red; knots pellucid ; 
sporidia involucrated ...... » heywaiors qufeso\ GRIRRITSIAN Sly. 
Thallus red, gelatinous ; 
branches in whirls; thece naked ...... Bornricuivus. 32. 
Thallus green, gelatinous ; 
branches in whirls; thece naked BarracHosPpeMuM. 33. 
B. Thallus jointed, coriaceous, or membranaceous ; main 
stem solid, or compoundly jointed ; sporidia enclosed in thece. 
Hutchinsidee. 
Thallus olive-green ; 
branches in whirls; joints simple.... CLADOSTEPHUS. 34. 
Thallus olive-green ; 
branches 2-rowed; joints compound .. SPHACELARIA. 35. 
Thallus red ; 
branches scattered; joints simple; .......- Exwisius.- 36. 
Thailus red; 
branches scattered; joints compound ... Hutcurnsra. 37. 
Thallus red, pervaded by a 
Centra], jomted axis .......-...++s++, VERTEBRATA. 38. 
