297 
Littorina parva 
iM Ske” SE Radula 21 m.m. 
2, ars sd SLED TBER 
3. USBEE £; SER DR RE 
Å. — 74" - Hi sg 3 
5. —, 145 ,- len SE 15e 
6) fan ulyst. eee 
Øg — 16 - — 37 - 
< 8. LG res re SEE 
9. er gg. ka Roe 
10. Ene 1 RET Es 
Littorina littorea 
1. Shell 14 m.m. Rudula 28 m.m. 
2. inn elgeke DE ERE 
3. — "17 - — 31 - 
4. mm regeres SAR é 
5. — 20 - i — 46 - 
6. Rd re — ÅåÅ7 - 
1: — 259 - — 48 - 
8. df sØ8banlos — 54 0 
9. BRS RB 
ie se Bø FS bb == 
From these and Teilman-Friis's figures et may be concluded that 
small dwarfed' forms have om an aåveragé a proportionally longer 
radula than the well developed specimens, but no constant charac- 
teristic separating the two forms can be deduced from the relative 
ength of the radula: 
The number of denticles in the lateral teeth of Littorina litto- 
rea greatly. differs in the. figures, of Lovén (6); Woodward (13),: and 
G. 0. Sårs (20), but it” must not be concluded from this that any 
great variation takes place. None of. these authors has treated the 
yeeth separately, but without doing so it is almost impossible to 
