13 



Denne art forekom tenunelig almimlelig i juni — juli 

 nianned ved EspewTr og Roniineloen i en dybde at 4-8 

 favne. I Bergens museums samling har jeg ligeledes paa- 

 trnftet et enkelt exeni])lar uden lokalitetsangivelse. I uni- 

 versitetets samling fiudes nogle faa cornii fra Horlovær (Sårs) 

 under navnet amaroucimn gilvinii. 



Aplidiopsis, Lalulle, 1887. 



Lahille opstiller som de vigtigste slægtskarakterer : 

 „Ingen vridning af tarmen. Ventrikelen glat. Postabdo- 

 men ustilket.-' Naar undtages ventrikelens dannelse frem- 

 byder denne genus storre lighed med aplididae end med 

 polyclinidae. hvad navnet ogsaa tyder paa; men da de sidst- 

 nævnte aldrig hai- ventrikelens vægge glatte, men denne 

 altid forsynet med større eller mindre ujevidieder, bliver 

 apJidiopsis alligevel at henføre under polyclinidae, selv om 

 det kunde synes ligesaa naturligt at henregne denne til de 

 første som at atopogaster, Herdman og puhjclinoides. Drasche 

 med foldede, ventrikelvægge er stillet ind under polyclinidae. 



Blandt de norske synascidier har jeg fundet 2 after, 

 som jeg vil henregne til denue genus. Disse har indbyrdes 

 flere ydre ligheder f. cx. begge har usædvanlig lang post- 

 abdoraen, hvorved de afviger fra Lahilles type : aplidiojisift 

 vitreus. Ligeledes er begge arters koloniform nogenlunde 

 ens: stor og globuløs; endelig har de begge en fast eller 

 bruskagtig fælles tunica. Forresten er de yderst forskjellige, 

 hvad individernes anatomi angaar: ventrikelens form, bran- 

 chialsækkens dannelse o. s. v. Den ene apli(li()2}si,i pomnm 

 viser ogsaa till)oilighed til at have en stilket postabdonicn, 

 idet enkelte individer har dennes ovre del noget indknel)en. 

 Maaske vil de ved en mere indgaaende anatomisk exaniina- 

 tion end den, jeg har haft anledning til at foretage med 

 det middelmaadige materiale, der har staaet mig til tjeneste, 

 kunde give anledning til opstillen af en ny genus. Fore- 

 lobig vil jeg henføre begge arter til slægten aplidiopsis. 



Aplidiopsis, Lahille, 1887. 

 Aplidiopsis pomiim. Sårs. 1851. 



(T:il.. I. Hy. S — lU). 



1851. Amaruuciam pomiuu. Sårs. Nyt ^lag. tor Nat. 



Bd. VI. 

 Som supplement til Sars's beskrivelse skal anføres: 



Det største exemplars maal var følgende: diameteren 

 8 cm., høiden 7 cm. Cormus incrusterer ialmindelighed 

 smaa sandpartikler jevnt fordelt over det hele. Fra Bohus- 

 liin har jeg dog seet cormi ganske uden nogen incrustation. 



This species was of very .aeneral occurrence in June 

 and July at Espeva-r and Bomnieloen, at a depth of from 

 4 to 8 fathoms. In the Bergen Museum collection, I have 

 met witli a single speeinien. of which the locality was not 

 given, ln the University collection tliere are a few cormi 

 from Herlovu'r (Sårs) under the name Amarouciuni gilvam. 



Aplidiopsis, Lahille, 1887. 



Lahille gives as the most important generic marks: 

 ,,No twisting of the intestine. Ventricle smooth. Postab- 

 domen sessile". A\'ith the exception of the formation of the 

 ventricle, the genus bears a greater resemblance to Aplididæ 

 than U) Polyclinidae, as the name also implies; but as the 

 ventricle in the latter never has smooth, bnt always more 

 or less uneven walls, Aplidiopsis must nevertlieless be 

 classed under Polyclinidæ, even though it might seem just 

 as natural to refer it to Aplididæ, as to placc Afopogastei: 

 Herdman, and Foh/clinoides, Drasche, with their folded 

 ventrirular walls under Polyclinidæ. 



Aniong the Norwegian Synascidians, 1 have found 

 2 species which I shall refer to this genus. These liavi.- 

 mutually several external points of resemblance, e. g. Ixith 

 have an unusually long post-abdomen, thereliy differing from 

 Laliille's type, Aplidiopsis vitreus. The shape of the colony 

 in botli forms is also somewhat similar, being large and 

 globular. Lastly, tliey iioth have a tirm or cartilaginous 

 common tunic. ln other respects they are extremely dis- 

 similar, as i-egards the anatomy of the members, the shape 

 of the ventricle, the formation of the branchial sac, etc. 

 One of theni, Apliilinpsis pomiim, shows a dis])osition to- 

 wards a stalked post-abdomen, the upper portion in some 

 of the members l)eing somewhat constricted. Perhaps a 

 more thorough anatomieal examination than I have been 

 able to make with the indifferent material at my disposal, 

 might occasion the establishment of a new genus. Mean- 

 while, I shall class ijoth species under the genus ^4^;//- 

 diopsis. 



ahille, 1887. 



Aplidiopsis 



Aplidiopsis pomum, Sårs, 1851 



ll'l. 1. tigs. s— 10). 

 1851. A)naronciinii pomum. Sårs. Nyt ^lag. for 



Nat. 



Bd. VI. 



The following particulars are added as a supplcnn-nt 

 to 8ars"s desci'iptiou: 



The dimensions of the largest specimen are as follows: 

 diameter, 8 cm., height 7 cm. The cormus is usually in- 

 crusted with small particles of sand, evenly distri])uted over 

 the whole surface. I have, however, seen cormi from Bo- 

 huslan ijuite free from incrustation. 



