Protozod and Rotifera at Havana, III. 329 



50. A. radiata Zach. ('94). 



One example observed by Dr. Kofoiil in plankton from the 

 river at E, in May. 



Subfamily SALPiNGOEClNiE. 

 Salpingceca James-Clark. 



Loricated, solitary, attached directly or by pedicel. 



51. S. minuta Kent. 



This extremely small form was found attached to the 

 loricse of Dinohryon serttdaria from the river, in May. ■ 



Order DINOFLAGELLATA. 



Suborder DINIFEEA. 



Family PERIDINID-ffi. 



Peridinium Ehrbg. 



Free-swimming, covered with an ornamented shell en- 

 circled by an equatorial groove, dividing the shell into two 

 similar halves, the anterior formed of thirteen or fourteen 

 plates, the posterior of seven, two of which, nearest the pos- 

 terior extremity, are each often drawn out distally into a 

 horn-like prolongation. A moderately wide longitudinal 

 groove extends back from the equatorial groove at the middle 

 of the ventral surface. Two tiagella, one of which lies in the 

 equatorial groove. 



52. P. tabulatum Ehrbg. 



Found in July and August, but only in Thompson's and 

 Matanzas lakes, abundantly in the former situation though 

 not in any of the intervening waters. 



Ceratitjm Schrank. 



Differing from Peridinium especially in the form and 

 structure of the shell. This is somewhat flattened dorso- 

 ventrally, with a broad uncovered area on the ventral surface ; 



