OCCURRENCE OF A ROTIFERON IN VAUCHERIA. 263 



Fig. 28, 29. Chitonellus distortus, Kirkby. Intermediate plates 5 y, anterior 

 process of insertion : c, denticulated portion ; e, median keel. Magni- 

 fied rather more than four times. 



30. . Another plate. Magnified four times. 



31. Chiton Lqftusianus, King. Anterior plate. Magnified rather more 

 than two diameters. 



32 to 37. . Intermediate plates (in some cases restorations) ; a, 



apophyses. Rather more than two diameters. 



38. . Posterior plate; a, apophyses. Magnified rather more thaa 



two diameters. 



39. . Lateral view of a posterior plate.* Magnified. 



40. . Lateral view of an intermediate plate. Magnified. 



41. ~-. Greatly enlarged view of one of the processes of attachment. 



42. Chiton Hoios^mhus. Kirkb}''. Anterior plate, showing sulcations on the 



surface. Magnified four times. 



43 to 48. . Intermediate plates, in some cases wholly restored; 



one of the figures (fig. 43) is from a sulcated specimen. Magnified 

 four times. 



49. . Posterior plate, showing faint indications of lines radiating 



from the apex. Magnified three times. 



50. Lateral view of a posterior plate. Magnified. 



51. . Intermediate plate, showing processes of attachment. En- 

 larged. Humbleton Hill. 



52. . Lateral view of the same plate. Magnified. 



53. Chiton Howseamis, Kirkby. A greatly enlarged view of one of the 



processes of attachment. 



54. Frontal aspect of an anterior plate. Species unknown (possibly C. 



cordatus.) Tunstall Hill. 



55. The same plate, seen from above. 



XXI. — Note upon the Occurrence of a Eotiferon in Vaucheria. By 

 Daniel Oliver, Jun., F.L.S. Plate XIV. 



Some observations which I made two or three years ago upon 

 certain singular, lateral appendages of the filaments of a species 

 of Vaucheria, collected at Prestwick Car, appear to me worthy 

 of a brief published notice, especially that I am able, from 

 several sketches made at the time, to furnish illustrative outlines 

 of them. Similar structures have been observed by Professor 

 Morren, of Liege, who describes them in a " Bulletin" of the 



* Some specimens of this plate are not so steep posteriorly as the original of this figure. 



