Prof. Bailey on Fossil and Recent Infusoria. 329 



" Has duas formas Prof. Bailey primus observavit et delineatus misit. 

 Multa specimina ipse vidi." Ehr. I. c. p. 19-20. 



These well characterized species are very abundant in the Ber- 

 muda Tripoli, but have not been detected at any other locality. 



6. " Triceratium Solenoceros. (Fig. 23.) — Testulse lateribus profunda 

 concavis, apicibus longe tubulosis radialis subacutis superficie granulo- 

 rum seriebus radiantibus rectis ornata, granulis in y^g- lineee 15. Diam. 

 2^3"'. Bermuda. 



" Prof. Bailey hujus iconem circumscriptam misit. Nonnulia speci- 

 mina ipse inveni." Ehr. I. c. p. 26. 



This remarkable species is easily recognized by the excessively 

 elongated angular processes. 



7, '■'• ZygocerosJ Bipons. (Fig. 24.) — Testula a latere lanceolata 

 utroque apice acuto et corniculo admodum parvo instructo, stricturis 

 mediis Isevibus duabus, superficie subtiliter granulata nee radiata. Diam. 

 ^V". Bermuda." Elir. I. c. p. 26. 



The true nature of this form is unknown. It is quite common 

 in the Bermuda earth. 



For an account of many other interesting forms from Bermuda, 

 I must refer to Ehrenberg's own memoir. A Hst of all the species 

 noticed by Ehrenberg is given in the table on pages 331-335, by 

 which it will be seen that this remarkable infusorial deposit agrees 

 with those of Virginia and Maryland in containing many species, 

 such as Evpodiscus Rogersii, Goniothecium Odoniella, various 

 species of Rhizosolenia, Dicladia, &c. which have hitherto been 

 considered as exclusively American forms. It is also remarkable 

 that the Bermuda specimen, like all those from Virginia, contains 

 no trace of calcareous Polythalamia, although I have found these 

 to be very abundant in specimens of recent sands and limestones 

 of the Bermuda Islands. 



The occurrence of this remarkable infusorial formation at Ber- 

 muda is of much interest, as i| shows that such formations are not 

 confined to the harbors and estuaries of a continent, but may 

 also occur on the "still vexed" shores of the lone isles of the 

 ocean. 



It is also remarkable that a deposit so purely siliceous could be 

 formed among the coralline isles of Bermuda. No mention of 

 any such "Tripoli" is contained in any of the accounts of the 

 geology of those islands which I have yet seen. It is therefore 



