78 MARINE FAUNA OF ST. ANDREWS. 



Littorina litorea, L. Op. cit. iii. p. 368, v. pi. 65. f. 5 & o a. 

 Between tide-marks in vast numbers. Often eaten. 



Genus 3. Rissoa, Freminville. 

 Eissoa parva, Da Costa. Op. cit. iv. p. 23, v. pi. 67. f. 3 & 4. 

 In great numbers on the seaweeds in the laminarian region 

 all round, especially off the East Rocks. Var. interrupta is 

 also common in shell-sand. 



Bissoa striata, Adams. Op. cit. iv. p. 37, v. pi. 68. f. 2. 

 Common under stones between tide-marks. The var. arctica 

 is the prevailing form. 



Rissoa soliita, Philippi. Op. cit. iv. p. 45, v. pi. 68. f. 7. 

 Occasionally in deep water and in shell-sand. 



Rissoa semistriataj Mont. Op. cit. iv. p. 46, v. pi. 68. f. 8. 

 From deep water and in shell-sand ; not common. 



Genus 4. Hydrobia, Hartmann. 

 Hydrohia ulvce, Pennant. Op. cit. iv. p. 52, v. pi. 69. f. 1. 

 In great abundance in the brackish pools near the mouth of 

 the river Eden. 



Fam. 11. SkeneidsB, Clark. 

 Genus 1. Skenea, Fleming. 

 Skenea plariorbis, Fab. Op. cit. iv. p. 65, v. pi. 70. f. 1. 

 Common in rock-pools amongst Geramium and other algae. 



Genus 2. Homalogyra, Jeffreys. 



Homalogyra rota, Forbes & Hanley. Op. cit. iv. p. 71, 

 V. pi. 70. f. 3. 



In shell-debris from the West Sands. Dead. 



