HYDROIDA 



55 



From the reptant stolons proceed polyp stems up to I2 mm. long, generally unbranched; more 

 rarely 2—4 polyp stems proceed from a common trunk, 1—2 nun. high. The polyps attain a length 

 of 0.7 mm., and are fusiform, with 6 — 12 tentacles placed in a whorl. Below the tentacles the polyp 

 is surrounded by a pseudohydrotheca, which it is very difficult to observe on the polvp when wholly 

 extended. In general it is jellied and vigorously developed. The polyp stems are, particularly in their 

 proxiuuil part, irregularly wrinkled. 



The very large gonophores show no medusoid structure; they are attached to the reptant sto- 

 lons by a short stem. 



Material : 



Greenland (Lille Hellefiskebanke) (the original s])ecimen of Garvria grornlandica Levinsen). 



An examination of the original specimen of Gnrvcia grocnlaiidica shows no difference at all 

 from Norwegian specimens of Pcrigo)iiiints rosais. The species are no doubt identical. If we compare 

 Kramp's drawing of Garvria gronilaiidica (1911, pi. XXV, fig. 6) with Jaderholm's figure of Pc- 

 rigoiiiiiius rosciis (1909, Taf. Ill, Fig. 7), there may, at the first glance, seem to be some points of 

 difference. Thus the stems of the specimen mentioned by Kramp are much shorter. But this character 

 proves of little significance if we compare the specimen with a larger colony, where, as a matter of 

 fact, the length of the polyp stems varies greatl\-. A greater stress might, on the other hand, be laid 

 on the apparently great difference between the pseudohydrothecae as represented in the two figures. 

 However, much depends on the contraction of the polyps and on the state of preservation, as is plainly 

 to be seen by an inquir\- into a larger material. I have several times had the opportunity of observ- 



200 m. . 600 m. ._ 1000 m, 2000 m. 



Text-fig. R. The occurence of Perigonimus roseiis in the Northern Atlantic. 

 (In tint hutched region the occurence according to the Htterature is common allthough scattered). 



