IQ22. No. 6. \UDIBRANCHFAUNAEN I [)ROBAKSUNDET, 9 I 



Systematic Summary. 

 Fam. Aeolididae. 



A. Triseriatiw. 

 Genus I. Coryphella Grav. 



In the diagnosis of the genus should be added: "The lateral teeth of 

 the radula most often denticulated", as both C.pelhicida and C. stimpsoni 

 have smooth lateral teeth. 



C. rafibranchialis (Johnston) Gray. 



PI. I. Fig. 1-3. 



New to the Kristianiafjord fauna '. Very common. Length up to 35 

 mm. The colour of the liver processes vary between red brown and yellow. 

 As a rule, there are 18 crossrows of teeth in the radula. Teeth have vary- 

 ing number of denticles, the median tooth as a rule 5 — 8, the lateral teeth 

 7 — 9 denticles. The lateral teeth some times with the apex curved inwards. 

 The spawn occurs in April-May. 



C verrucosa (Sars) F. cS: H. 



PI. I. Fig. 4. 



New to the Kristianiafjord fauna. Rare in 19 19 and 1920 and \er_v 

 common in 1921. Length up to 22 mm. Generally speaking the liver pro- 

 cesses have been found to be much lighter in colour than they should be 

 according to Sars' (1829, p. 9) diagnosis. Mature individuals and spawn 

 have not been observed. It is doubtful whether C. verrucosa can be main- 

 tained as a separate species. In the Drobak Sound numerous intermediate 

 stages have been found between this form and C. nifibraiichialis with regard 

 to e.xternal characters, and in the radula no definite difference between 

 the two species can be demonstrated. As I have not, however, seen the 

 spawn of C. verntcosa I have classified it preliminarly as a separate species. 



C. lineata (Lovk.n-) A. & H. 



PL II. Fig. 5. 



New to the Kristianiafjord fauna. \'ery rare. Length up to 15 mm. 

 The cerata have up to 4 white longitudinal lines. Radula has 15 — 16 cross 

 rows of teeth. The middle tooth has 7 — 10 denticles, the lateral teeth 8 — 11. 

 One mature indi\'idual was found on Aug. 3rd 1920. 



C. landsburghii. (A. & Hi. Gray. 



PI. II. Fig. 6.. 



New to the Kristianiafjord fauna. Only one single specimen observed. 

 Length 9 mm. E.xternal characters accord with A. & H'.s picture and de- 

 scription of the species. Radula not examined. 



' See ".MerkiL^d" in the Introduction. 



