EXPLANATION OF PLATE XXV. 

 FIG. 



1-5. PERIDINIUM TABULATUM, Ehr., vol. i. p. 448. i, Variety with rounded poles or 

 apices and no eye-like pigment-spot, ventral aspect, x 350 (Claparede and 

 Lachmann) ; 2, variety with pointed apices, dorsal aspect (Ehr.) ; 3, 

 separate reticulated plate from cuirass, x 600; 4, encysted example, with 

 eye-like pigment-spot (C. & L.) ; 5, example with four pigment-spots, its 

 cuirass cast off (C. & L.). 



6, 7. PERIDINIUM APICULATUM, Ehr. sp., vol. i. p. 449, x 400 (Ehr.). 

 8-13. CERATIUM DIVERGENS, C. & L., vol. i. p. 453. 8 and 9, Empty cuirass, dorsal and 

 ventral aspects, showing form and disposition of its component plates, 

 x 500 (C. & L.); 10, encysted animalcule (C. & L.) ; n, example with 

 carapace cast off (C. & L.) ; 12 and 13, the same species as figured by Bailey 

 under the title of Peridinium depressum. 



14. PERIDINIUM JEQUAHS, S. K., vol. i. p. 45 1. Dimensions unrecorded (WiU.-Suhm). 

 15, 1 6. PERIDINIUM SPINIFERUM, C. & L., vol. i. p. 449, x 400 (C. & L.). 

 17, 18. GYMNODINIUM FUSCUM, Ehr., vol. i. p. 443, x 300 (Ehr.). 18, Example of con- 

 jugation or longitudinal fission. 



19, 20. GYMNODINIUM PULVISCULUS, Ehr. sp., vol. i. p. 443, x 500 (Ehr.). 

 21, 22. GLENODINIUM ACUMINATUM, Ehr., vol. i. p. 446, x 250 (Ehr.). 



23. CERATIUM MICHAELIS, Ehr. sp., vol. i. p. 453, x 300 (Ehr.). 



24. CERATIUM TRIPOS, Miill. sp., var. MACROCEROS, vol. i. p. 454, x 250 (C. & L.). 



25. CERATIUM KUMAONENSE, Carter, vol. i. p. 458, x 190 (Carter). 



26. CERATIUM LONGICORNE, Perty, vol. i. p. 457, x 300 (Carter). 



27, 28. GLENODINIUM CINCTUM, Ehr. sp., vol. i. p. 446, x 400 (Ehr.). 28, An example 



of longitudinal fission or conjugation. 



29, 30. PERIDINIUM sp., encysted examples, vol. i. p. 447, x 250 (C. & L.). 

 31,32. CERATIUM FURCA, Ehr. sp., vol. i.p. 445, x 350. 32, Central region, showing 



more minute structure of the cuirass, x 600 (C. & L.). 



33. CERATIUM TRIPOS, Miill. sp., normal short-armed type, x 250 (C. & L.). 

 34, 35. MELODINIUM UBERRIMUM, Allman sp., vol. i. p. 445. 34, Normal animalcule, 



x 3 > 35> example dividing by transverse fission (Allman). 

 36. CERATIUM TRIPOS, Miill. sp., var. ARCTICUM, vol. i. p. 454, x 300. 

 37-39- PROROCENTRUM MICANS, Ehr., vol. i. p. 461. 37 and 38, Lateral and dorsal 



aspects ; 39, empty cuirass, x 303 (C. & L.). 



40. CERATIUM FUSUS, Ehr. sp., vol. i. p. 456, x 300 (C. & L.). 



41. PERIDINIUM RETICULATUM, C. & L., vol. i. p. 449, x 300 (C. & L.). 



42. DlNOPHYSIS VENTRICOSA, C. & L., vol. i. p. 459, X 3$O (C. & L.). 



43. DlNOPHYSIS ACUMINATA, C. & L., vol. i. p. 459, X 3OO (C. & L.). 



44. DlNOPHYSIS OVATA, C. & L., vol. i. p. 460, ventral aspect, x 350 (C. & L.). 

 45, 46. AMPHIDINIUM OPERCULATUM, C. & L., vol. i. p. 461, x 300 (C. & L.). 



47-50. PERIDINIA sp., encystments, vol. i. p. 448, with contents variously divided, that 

 at 49 with the contained protoplasmic mass separated into eight minute 

 naked Peridinia, x 300 (after Claparede and Lachmann). 



51, 52. DIMASTIGOAULAX CORNUTUM, Ehr. sp., vol. i. p. 462, front and lateral aspects, 

 x 300. 



53. GYMNODINIUM ROSEOLUM, Schmarda sp., vol. i. p. 444, x 350 (Schmarda). 



54. GYMNODINIUM INERME, Schmarda sp., vol. i. p. 44/1, x 600 (Schmarda). 

 55-57- PERIDINIUM TABULATUM, Ehr., vol. i. p. 448, brown variety with cleft anterior 



border, x 300. 55, Ventral, 56, dorsal, 57, lateral aspects, the example at 



56 enclosing a recurved band-like endoplast. 

 58, 59. GYMNODINIUM LACHMANNI, S. K., vol. i. p. 444. At 58 an example dividing 



by longitudinal fission, x 300 (C. & L.). 

 60, 61. GYMNODINIUM MARINUM, S. K., vol. i. p. 444, x 600. At 61 an example 



devouring a smaller monad. 

 62. CERATIUM BICORNE, Schmarda sp., vol. i. p. 453, x 400 (Schmarda). 



