302 Mr. J. Ralfs on Chantransia. 



connexion with the auricle, and likewise with the efferent vessels 

 from the papillse ; e, portal heart lying under the pericardium and 

 opening through its floor; /, efitrent vessels from the branchial 

 papilla?. 



Fig. 4. Central ganglions and their nerves: — a, a, cerebroid ganglions; 

 b, b, branchial ditto ; c, c, pedial ditto ; d, d, olfactory ditto ; 

 e, e, buccal ditto ; /, /, gastro-oesopliageal ditto ; </, nervous cord, 

 connecting the infra-cesophageal to the supra-oesophageal gan- 

 glions, forming the anterior collar ; h, small middle collar ; i, great 

 oesophageal collar; 1st pair of nerves go to the dorsal tentacles; 

 2nd pair to the upper portion of the channel of the mouth and 

 lips ; 3rd and 4th pairs go likewise to the channel of the mouth 

 and lips ; 5th pair supply the skin at the side of the head ; 6th 

 and 7th pairs pass to the skin at the side of the back, and supply 

 the branchial papUla; ; 8th and 9th pairs go to the foot ; 10th pair 

 are the lingual nerves ; 1 1th pair supply the muscles of the buccal 

 mass ; 12tli pair supply the giUlet and stomach ; 13th pair go to 

 the glands of the papillae ; 14th is a single nerve going to the re- 

 productive organs ; 1 5th is likewise a single nerve, and probably 

 also goes to the same organs. 



Fiff. 5. Interior view of one of the jaws : — a, cutting edge ; 6, point at 

 which the two jaws are articulated ; c, expanded lobe at the dorsal 

 margin for muscular attachment. 



Fig. 6. External view of the same : — a, cutting edge ; b, expanded lobe at 

 the dorsal margin. 



Fig. 7- Two of the spinous plates from the tongue. 



Fig. 8. Transverse section of a branchial papilla : — a, gland ; b, afferent 

 branchio-cardiac vessel ; c, efferent ditto. 



XXIV. — On Chantransia, Desv. By John Ralfs, Esq.* 



Chantransia, Desv. Trentepohlia, Agardh and British 

 authors. 



Plant affixed, tufted; filaments branched, jointed, monosipho- 

 nous; fructification — capsules with granular contents and 

 usually terminal and suhcorymbose on proper branches. 



Freshwater, minute, tufted Algse of a red, purplish or inky colour. 

 Filaments much branched, jointed ; main branches elongated, 

 mostly level-topped. Fructification capsular, usually on short, 

 much divided proper branches ; capsules generally crowded, 

 subcorymbose, and terminal on short stalks, their contents 

 simple. 



The proper position of this genus is doubtful : in habit and 

 appearance some of its species agree so closely with the minute, 

 parasitic, irregularly branched species of Callithamnion, that Dr. 

 Harvey in his ' Flora Hibernica ' united it to that genus ; and 

 although, at Mrs. Griffiths' suggestion, he has, in his ' Manual of 



* Read before the Botanical Society of Edinburgh, June 19, 1851. 



