1853.] 



431 



productis obtusis, superficie triquetra 'ellulis magnis hexagonis favosa. Hab. 

 Mindanao. 



13. Triceratium WiLKESii, H. et B. ; lovica, lateribus convexlusculis angulis 

 rotundatisj superficie ut in T. concavum notata. Ilab. Puget's Sound. 



Ap2)e7idix. 



14. Lagena Williamsoni, H. et B. ; testa bicellulosa, cellulis diversis, infe- 

 riore ellipsoidealongitudinaliter costata in isthmum infundibuliformem attenuata, 

 et ad cellulam superiorem glabram senai-lagenajformem (vel inverse infundi- 

 buliformem) ferruminata ; collo breviusculo recto, ore subampliato. Hab. Min- 

 danao. 



List of DiatomacecBi collected by the. United States Exploring Exjjedition under 



Capt. Willcsy IT. S. N. 



By Prof. J. W. Bailey. 



Although no collection of the Diatomaceae was purposely made by the Ex- 

 ploring Expedition, a careful examination of various specimens of marine mud, 

 &c. adherins: to the algae, shells, he, which were brought honie by Capt. Wilkes, 

 was rewarded by the discovery of many interesting forms, a list of which is here 

 given in the order of their geographical distribution. 



JPuget's Soicad, Oregon. 

 D1AT0.MACE.E. 



Actinoptychus senarius, Ehr. 



*Aulacodiscus Oreganu?, H. et E. 



*Amphitetras Wilkesii, H. et B. 



Arachnoidiscus Ehreribergii, Bailey 



*Cocconeis rhombifera, H. et B. 



* f' sulcata, H. et B. 



Coscinodiscus oculus-iridis, Ehr. 

 " radiatus " 



" excentricus " 



Epithemia gibberula, Kiitz. 



Grammatophora angulosa, Ehr. 

 " stricta, " 



Grammatophora undulosa, Ehr. 



Isthmia obliquata 



Rhabdonema arcuatum, Kiitz. 



Surirella fastuosa, Ehr. 



*Triceratium Wilkesii, H. et B. 

 Spo7igiolitesy 4*c. 



Spongiolites A^aricus, Ehr. 



Dictyocha splendens, Ehr. This is now 

 known to be a calcareous plate from a 

 species of Synapta. It dissolves in 

 acids, and polarizes light. 



Sa7i Francisco, Calif ornioy. 



Arachnoidiscus Ehrenbergii, Bail. 

 Cocconeis scutellum, Ehr. 

 Gomphonema minutissima, Ehr. 



Terra del Fuego. 



Entopyla australis, Ehr. 

 Grammatophora serpentina, Ehr. 

 ' sti-icta " 



Climacosphocnia australis, Kiitz. 

 Grammatophora oceanica, Ehr. 

 *Isthmia minima, H. et B. 



Stauroptera aspera, Ehr. 

 Cocconeis scutellum, " 

 Actinoptychus senarius, Ehr. 



"Rio Janeiro. 



Dictyocha splendens, Ehr. 

 Spongiolites anchora, " 

 Both of these come from the calcareous 

 particles of an Echinoderm (Synapta). 



Valparaiso. 



Gallionella sulcata, Ehr. 

 Grammatophora hamata, Ehr. 

 Dictyocha speculum, " 



