KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:o 5. 14] 
l. c. by Rurrecur. He compares it — and he is quite justified in doing so — with 
Cruoria pellita Harv. Phye. Brit. pl. 117, but he says that the Ochotsh plant differs 
in some respects from the English one. This accords well with my own observations. 
The differences between the English-French Petrocelis cruenta and Ruprecut’s Cruoria 
Middendorffii are in my opinion so considerable, that they ought to be regarded as 
separate species. The alga found by me on the coast of Finmarken differs, just as the 
Ochotsh form, from the more southern Petrocelis cruenta by a more strongly developed 
basal layer, by the vertical cell-rows being often branched, and, above all, by the diffe- 
rent shape and position of the tetrasporangia. In 1. cruenta these are developed above 
the middle of the vertical cell-rows. Cp. Lu Joris Liste Alg. Cherb. t. 3 and Iu- 
PRECHT I. c. 
Habitat. The present species has been found in the Polar Sea growing on rocks 
and stones between tide-marks on exposed coasts. Here it has young tetrasporangia in 
course of development in September. 
Geogr. Distrib. Within the Polar Sea it is known only from the north coast of 
Norway. Its only certain Locality is Oxfjord at the mouth of Altenfjord. 
Petrocelis cruenta J. G. Aa. 
Spec. Alg. 2, p. 490. 
Descr. Petrocelis cruenta J. G. Ag. 1. c. 
Fig: » » Tuur. in Le Jol. Liste Alg. Cherb. t. 3, fig. 3—4. 
Syn. Petrocelis cruenta Kigen, Nordl. Aly. p. 14. 
Remark on the determination of the species. In KuEEy’s collections from Nordlanden 
there are some microscopical preparations of that alga in a sterile condition which, in 
his list of the alge of Nordlanden, he names Petrocelis cruenta. Judging from these 
preparations, this plant scems really to be another species of Petrocelis than the LP. 
Middendorfjit occurring on the coast of Finmarken. But on the other hand [ am un- 
able to decide with certainty whether the plant from Nordlanden is identical with the 
P. cruenta occurring on the coasts of France and England, or with the P. Ruprechtii 
common on the western coast of Sweden. This cannot be decided by means of ste- 
rile specimens. Accordingly I think I ought to adhere to the determination madc 
by Kuen. 
Habitat. The present alga grows, according to Kieren, ou rocks between tide- 
marks on exposed coasts as well as in the interior of bays. Only sterile specimens 
are known from the Polar Sea; they were collected im summer. 
Geogr. Distrib. It is known only from the southern part of the Atlantic region 
of the Polar Sea. 
Localities: The Norwegian Polar Sea: Nordlanden, common and abundant. 
