20 



MICROSCOPICAL OBSERVATIONS 



ST. AUGUSTINE, FA. 



March 16th, 1850. The mud of the St. Sebastian River, collected at the 

 bridge west of St. Augustine, proved to be very rich in siliceous shells of recent 

 and living Diatomacese, among which the following were noticed, viz : 



Actinoptychus senarius, Ehr. 

 Actinocyclus, several species. 

 Biddulphia pulchclla, Gray. 

 Coscinodiscus excentricus, Ehr. 

 " lineatus, Ehr. 



oculus-iridis, Ehr. 



subtilis, Ehr. 

 Dityocha fibula, Ehr 

 *Eupodiscus radiatus, B. 



Rogersii, Ehr. 

 Gallionella sulcata, Ehr. 

 Meloseira salina, Kg. 



fNavieula elongata. 



baltica, Ehr. 

 *Pinnularia Couperi, B. 



lyra, Ehr. 



*Pyxidicula compressa, B. 

 Rhaphoncis rhombus, Ehr. 

 Stauroptera aspera, Ehr. 

 *Surirella circumsuta, B. 

 splendida, Ehr. 

 Triceratium favus, Ehr. 



hexagonalis, B, 



O 



Zygoceros rhombus, Ehr. 



The following Algie were found at the same place, viz : 



Bostrichia scorpioides ? Mont. 

 Delesseria hypoglossum, Lamour. 

 Leprieurii, Mont. 



Porphyra vulgaris, Ag. 

 Ulva latissima, L. 



ST. AUGUSTINE. continued. 



In the mud at the foot of the sea wall, near the old Spanish Fort St. Marco, I 

 noticed the following Diatomacea;, viz : 



Ceratoneis closterium. Ehr. very active. 

 Coscinodiscus lineatus, Ehr. 

 " radiatus, Ehr. 



subtilis, Ehr. 



Grammatophora marina, Ehr. 

 Navicula baltica, Ehr. 

 " sigma, Ehr. 



The following Alga> were also noticed at the same locality, viz : 



Bostrichia scorpioides ? Mont. 

 Callithamnion, undetermined. 

 Ectocarpus siliculosus, Lyngb. 

 Gelidium corneurn, Lamour. 



Gracilaria multipartita, Clem. 

 Rhabdonia Baileyi, Harv. 

 Spyridia filamentosa, Wulf. 



f Specimens which I received from London, agreeing well with our own, were marked N. elongata, but 

 by whom they were so named I do not know. I had been in the habit of calling it N. diagunalis, but had 

 not published any notice of it. Its delicate diagonal, transverse, and longitudinal rows of dots make it an 

 interesting microscopic object. 



