174 
This species is only little variable in shape and size. It often reaches a length 
of 14 em, even in the Baltic, almost to the limit of its distribution. The largest 
specimens, 18 cm high, were found in the Skagerak and the South Fyen waters. 
The depth has no influence on its size, save that when growing at low-water mark it 
does not become longer than 6 em. The greatest length is reached in 5,5 to 9,5 meters 
depth. Adventitious shoots from scars left by decayed ends of frond frequently 
occur, as in Furcellaria, but rarely developing from the surface of the frond. 
The species grows on stones, but is frequently met with loose on the bottom, 
particularly in the Zostera formation, but also on bare sandy bottom, as for instance 
around Anholt, where it occurs in great quantities together with Furcellaria fastigiala. It 
occurs in all the Danish waters, with exception of the eastern Kattegat and the Baltic 
around Bornholm, from a little below low-water mark to about 11 meters depth. In 
greater depths it occurs more rarely; certainly it has been found in several places down 
to 23,5 m depth, but in most cases it was certainly or probably loose. As sure 
deeper localities may be named, in the Skagerak: off Hanstholm and Lonstrup, 13 m; 
and in the Kattegat: Tonneberg Banke, 16 m. It does not thrive in fjords; in the Lim- 
fjord it has however been found in one locality. 
Specimens with tetraspores seem to occur much more rarely than sexual spe- 
cimens in the Danish waters; I have met them only in one locality in the Skagerak 
and in two in the northern Kattegat, while female specimens have been found in 
several places from the Skagerak to the Baltic. 
Localities. Ns: Orhage, 2m. — Sk: Hanstholm, 5,5 to 13 m, abundantly in 13 m depth; washed 
ashore by Blokhus and Svineklev (P. Petersen); off Lønstrup 8,5—13 m, most well developed in 8,5 m 
depth; Hirshals, near land 1—4,5 m, in some places dominant. — Lf: Only found on the mole of Lemvig, 
6 cm long. — Kn: Harbour of Skagen; Hirsholmene; Krageskovs Rev; Frederikshavn; N. Renner 1—5,5 m; 
several places north of Læsø, 2—9,5 m; Trindelen, about 18,5 m; Tonneberg Banke, 16m. — Km: NE, 
NW of Fornæs; around Anholt, abundantly loose. — Ks: Hesselo (Lyngbye). — Sa: PN (Kalovig); PE 
(Refsnæs); Hofmansgave (Hofman Bang, J. Vahl, C. Rosenberg): OA (Æbelø). — Lb: AX (Bjornsknude), 
9,5 m; Middelfart (Rasch, !); Fano Sund, 1m; DF; CC; DB; UX. At several places it reaches a length 
of 18cm. — Sf: CU. — Sb: GQ; harbour of Kerteminde; DO; Y; UR. — Su: North of Helsingør (Lieb- 
man, Joh. Lange, !); Taarbæk Rev; RK; PS, off Charlottenlund. — Bw: UY!, 18 m, probably loose. LC 
(Gulstav) ; South of Nysted. — Bm: QM (Juels Grund); washed ashore at Stevns. 
Fam. 7. Squamariaceæ. 
Petrocelis J. Agardh, 
1. Petrocelis Hennedyi (Harvey) Batters. 
Batters in Holmes Alg. Brit. Exsicc. No. 89 (non vidi), Mar. Alg. Berw. Tweed, 1889, p. 94, tab. XI, 
fig. 3—4. 
Actinococcus Hennedyi Harvey, Natural History Review, Vol. 4, 1857, p. 202, pl. 13 A, fig. 1 (non vidi). 
Cruoria pellita Lyngbye Hydroph. 1819, p. 193, tab. 66 ex parte, teste specim. 
Chetophora pellita Flora Dan. tab. 1728, 1821. 
Petrocelis Ruprechtii Hauck Meeresalg. 1883, p. 30. 
The species forms dark-red fleshy crusts, in a dried state glossy, 1—3 cm in 
diameter. The basal layer is a monostromatic disc composed of radiating filaments. 
