12 LIST OF CYCLOPHORID^. 



§ Periostraca spinulose. Mouth with a refiexed lobe near the suture. 



1. Pterocyclos Prinsepsi. 



Pterocyclos Princepsi Von Busch in Pfeiffer, I.e. 111. n. 3. ; 



Kuster, Chemn. Conch. Cab. i. 19. t. 24. f. 7. 10. 

 Steganotoma Princepsi Von Busch in Philippic Conch. Abbild. 10. 



t. 1. f. 6. 



a. India. Presented by Dr. Horsfield. 



2. Pterocyclos hispidus. 



Cyclost. spiraculum Sow. Thes. Conch, i. 110. n. 59. t. 31. f. 270— 



272. 

 Spiraculum hispidum Pearson, Jour. Asiat. Soc. Bengal, ii. 591. 



1833. 



Pterocyclos hispidus Benson, MSS. 



Hab. India. Perhaps the same as the preceding. 



§§ Periostraca smooth. Mouth with a hole near the suture. 



3. Pterocyclos rupestris. 



Steganotoma pictum Troschel, Philippic Conch. Abbild. 105. 



t. 1. f. 5. 

 Spiraculum parvum Pearson, Jour. As. Soc. Beng. ii. 592. 1833. 

 Cyclostoma spiraculum var.y*. Sow. Thes. Conch, f. 273. 

 Pterocyclos anguliferus Pfeiffer, I.e. 111. n. 2. ; Kuster, Chemn. 



Conch, i. 19. t. 24. f. 3. 6. 

 P. rupestris Benson, J. A. S. Beng. i. 13. t. 2. f. 1. ; Pearson, 1. c.592. 

 Cyclostoma anguliferum Soideyet. 



a — c. India. 



d—f. Ceylon. Presented by H. L. Layard, Esq. 



g. Ceylon. Var. Presented by H. L. Layard, Esq. 



§§§ Uncertain. 



4. Pterocyclos Albersi. 



P. Albersi Pfeiffer, 1. c. 111. n. 5. and 151. n. 18. 

 Hab. ? 



5. Pterocyclos pictus. 



P. pictus Trosch.; Pfeiffer, 1. c. 111. n. 4.; Kuster, Chemn. Conch. 

 Cab. i. 19, t. 24. f. 21—25. 



Hab. ? 



Appears to be the same as Cyclotus planorbulus jun. 



