174 



This species is only little variable in shape and size. It often reaches a length 

 of 14 cm, even in the Bailie, 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 cm. 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 Fiircellaria, 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 fastigiata. 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; certain!}' 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 Hanslholm and Lonstrup, 13 m; 

 and in the Kattegat: Tenneberg 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: 0rhage, 2 m. — Sk : Hanstholm, 5,5 to 13 m, abundant]}' in 13 m depth; washed 

 asiiore by Biokhus and Svineklev (F. Petersen); off Lenstrup 8,5 — 13 ni, 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. - Kli: Harbour of Skagen ; Hirsholmene; Krageskovs Rev; Frederikshavn ; N. Banner 1 — 5,5 m; 

 several places north of LffiS0, 2 — 9,5 m; Trindelen, about 18,5m; Tonneberg Banke, KJm. — Km: NE, 

 NW of Formes; around Anholt, abundantly loose. — Ks: Hessela (Lyngbye). — Sa: PN (Kalavig); PE 

 (Befsnres); Hofmansgave (Hofnian Bang, J. Vahl, C.Rosenberg): OA (.Kbelo). — Lb: AX (Bjernsknude), 

 9,5 m; Middelfart (Rasch, !); FaMio Sund, 1 m; DF; CC; DB; UX. At several places it reaches a length 

 of 18 cm. - Sf: CU. - Sb: GQ; harbour of Kerteminde; DO; Y; UR. — Sii : North of Helsingor (Lieb- 

 man, Joh. Lange, !); Taarbtek Rev; RK; PS, off Charlottenlund. — Bw : UY\ 18 m, probably loose. LC 

 (Gulstav) ; South of Nysted. — Bin: QM (Juels Grund); washed ashore at Stevns. 



Fam. 7. Squamariaceae. 

 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, pi. 13A, fig. 1 (non vidi). 

 Cruoria pellita Lyngbye Hydroph. 1819, p. 193, tab. 66 ex parte, teste specim. 

 Chatophora 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. 



