176 



CRYPTOGAM I A. 



COSCI NODI SOUS RADIATUS, Ehr. 

 COSCINODISCUS EXCENTRICUS, Ehr. 

 DlCTYOCHA SPECULUM. Ehr. 



Epithemia gibberula, Kutz. 



* Aulacodiscus Oregonensis, Bail. & Harv. (Tab. 9, fig. 6.) 



A. lorica promentiw 13 intramarginalibus instructa, a quibus tot radii 

 fere ad umbonem procurrmt, superficie proater umbonem glaberrimum 

 minute punctata iridescente. 



Lorica with 13 foot-like processes near the circumference, from 

 which rays extend nearly to the centre. The whole surface, except 

 a small, smooth, circular, central space, minutely punctate and iri- 

 descent, as in many species of the genus Actinocyclus. 



Grammatophora angulosa, Ehr. 



Grammatophora stricta, Ehr. 



Grammatophora undulosa, Ehr. 



Isthmia obliquata, Ag. (I. nervosa, Kutz.) Abundant and large. 



Khabdonema arcuatum, Kutz. 



SURIRELLA FASTUOSA, Ehr. 



* Triceratium Wilkesii, Bail. & Harv. (Tab. 9, fig. 7, 8.) 



T. lorica lateribus convexiusculis, angulis rotundatis, super fide triquetra 

 cellulis minutis in lineas radiantes simplices furcatasque co-ordinatis 

 notata, prominentiis jugalibas punctulatis. 



Lorica with the sides slightly concave; the angles rounded; basal 

 faces triangular. Surface with small cells arranged in single and 

 forked radiating lines, as in Amphitetras Wilkesii. Connecting pro- 

 cesses of the three angles minutely punctate. 



Spongiolites Agaricus, and other species. 



SAN FRANCISCO, CALIFORNIA. 



Arachnodiscus Ehrenbergii, Harv. & Bail, supra, p. 174. 

 Cocconeis scutellum, Ehr. 



GOMPHONEMA MINUTISSIMA, Ehr. 



