HYDROIDA 



53 



Prrigniiiiints rrpriis is a soutlieni species which penetrates into our seas. It has been recorded 

 from tile Mediterranean and tlie west coast of France, and occurs frequently in the sea round Great 

 Britain and Ireland. AIread_v in the North vSea its occurrence is more straggling. In the Dani.sh 

 waters and along the coast of Bohuslan it is still rather frequent. On the coast of Norway it is not 

 unfrequently met with in the Trondhjemfjord, where the fauna, on the whole, bears a .southern char- 

 acter. But only once it has been found farther to the north, at Lofoten. vSiemundsson {1911) re- 

 cords several questionable specimens from the west and the north of Iceland. Ihit these localities 

 have to be confirmed. As a new locality must now be added the P'aroe Islands. The species belongs 

 to the literal region. 



200 m. 600/r ,%ooo m. , 2000m. 



Text-fig. P. The distribution of Pengonimus i;-p,-ns in the Northern Atlantic (o localities neetliug further confir- 

 mation. — In the hatched region the litterature denotes a scattered although common occurence of the .species). 



Perigonimus abyssi G. O. Sars. 

 1874 Prn'goiiii/iiis abyssi, G. O. Sars, Bidrag til Kundskaben om Norges Hydroider, p. 96, pi. 5, Fig. 27 — 30. 

 19H — sjj., Kramp, Danmarks-Ekspeditionen til Gronlands Nordostkyst, p. 363. 



From the reptant stolons proceed mibranched pol\p stems, which attain a length of 1.5 mm. 

 The polyps are about 0.5 mm. long, broadl\- fusiform, liearing 5—8, usuall)' 7 tentacles in a whorl. 

 Below the tentacles the pohp is surrounded by a rather \-igorous, wide, jellied pseudohydrotheca, wliich 

 is, however, often hardly visible on the polyp wholly extended. The polyp stems are irregularly and 

 strongly wrinkled, and have a dark-coloured, vigorous perisarc. 



The gonophores are developed into free medusae, having, when deliberated, a vigorously 

 developed umbrella and four tentacles. The gonophores are developed on the polyp stems, to which 

 they are attached by a \-cry short stalk. On the polyp stem arise one or two gonophores. 



