12 THÉEL. NORTHERN AND ARCTIC INVERTEBRATES. II. PRIAFULIDS, ECHIURIDS ETC. 



schliessen darf , dass ein Stuck abgebrochen war, : . . » . As is known, the proboscis is 

 easely broken away in several Echiurids. 



After that, several specimens of Hamingia arctica have been brought up in the 

 dredge from two different localities. Ray Lankester (1883) and Norman obtained 

 two specimens at the mouth of the Hardanger Fjord and låter on Skorikow (1901) 

 communicates that several specimens were dredged in the arctic Sea (Murman Sea?). 

 Thanks to these authors we now know how the matter stånds. Hamingia arctica is 

 really in possession of a true, well developed proboscis ; but the informations of Ray 

 Lankester and Skorikow as to its general appearance are not in full conformity, 

 the one with the other. The former investigator writes : » At f irst sight I was inclined 

 to suppose that the Gephyrean dredged this summer was not Hamingia, but a Tha- 

 lassema. It was about half the size of Koren's and Danielssen,s specimen, of a 

 bright apple-green colour, and had a long contractile proboscis resembling closely that of 

 Thalassema and Echiurus. The proboscis, when extended, was as long as the body !..»■. 

 Be-sides, in the »tabular statement» he says: »Frontal hood (so-called proboscis) as 

 long as the body when stretched, tapering towards the free end, narrow and 

 trough-like » . 



On the other hand, Skorikow writes as to the proboscis of one of his arctic 

 specimens: »Ein Exemplar wurde fur Museumszwecke in toto conserviert und ist nur 

 sein Russel etwas der Länge nach dabei verkiirzt.. Wie aus der Zeichnung ersichtlich, 

 die von ihm hergestellt ist, erinnert er sehr an den Bonellia-Russel. Er hat die Form 

 einer geschlossenen Röhre, d. h. die Ränders decken sich, dagegen wiirde er wohl 

 rinnenförmig sein bei einer Verkurzung im Querschnitt. Die Endlappen öder Schau- 

 feln verkiirzen sich bei der Zusammenziehung und rollen sich dabei auf. Der Russel 

 ist etwas kiirzer als der körperlänge, wodurck sich die Gattung Hamingia der Gattung 

 Thalassema nähert, während das in zwei Lappen auslaufende freie Ende des Riissels 

 auf die Gattung Sonellia hinweist. » 



The difference mentioned is not an unessential one and further investigations 

 may prove, whether the Norwegian form of Ray Lankester represents a species 

 different from the Arctic one described by Danielssen and Koren, Horst and 

 Skorikow. 



The survey below may prove that we have to do with two or three 1 groups 

 of northern Gephyrea, very little related indeed among themselves. 



Sub-Order Priapulida. 



Frontal hood or preoral lobe, tentacles, genital setae or papillse and bristles 

 absent. Anterior part of the cylindrical body thick, retractile and provided with 



1 The mysterious Saccosoma seems to deviate to such a degree from the true Echiurids. that I propose 

 to keep it separate, until further. 



