OEGANISMS IN ACADIA. 161 



Explanation of Plates. 

 Plate V. 



Figs. 1-3.— Bulhotrephis ardiqm, Brongn.— 1. From Brongniart's original figure.— 2. Example figured by Hisinger.— 



3. Example of tliis s|iecies from Div. Ih, Basal series, HanforJ Brook. See p. 1-1 1. 

 Fig. 4. — Fuconks cirdnnatus. Brongn. Brongniart's figure to illustrate the succeeding species. See p. 145. 



Fig. 5.— I'liycoidella slichidi/era, n. gen. et sp.— 5a, Part of barren frond (or brand i).— 5?;, Part of fertile frond (or 



branch).— 5f, Stichidium, mag. f.— 5rf, A sporangium (?) further magnified. All from Div. lb, Basal 



series at Hanford Brook. See p. 144. 

 Fig. e.—Microphycv!' calmahis, n. gen. et sp.— ijfî. Portion of frond showing branches and nodes.— 6';, Fragments 



of frond showing triangular enlargements at the forks of the branches. From Div. 1'j, St- John Group 



Mag. 3 0. See p. 14». 



Plate VI. 



Fig. l.—Paln'ochorda setacca, n. sp.,— la. Group of fronds, reduced J.— 16, Fragment of three fronds to show th.e 

 annulation of the tubes, and the attachment of the setse.- Ic, Transverse section of frond, natural 

 size.— W, Same enlarged ; to show the ends of fusiform cells under the cuticle, and the irregular cells 

 of the interior.— If. Portion of frond, natural size, to .show rough granulated surface with transverse 

 ribs.— 1/, Portion of frond decorticated, showing the fusiform cells beneath the cortex.— 1^, Portion of a 

 seta Mag. f. All from Div. 16, Basal series, Hanford Brook. See p. 145. 



Fig. 2.—Hydrocytium (?) silicula, n. sp.. Frond showing contracted parenchyma. Mag. ^l'. From Div. 16, St. John 

 group. See p. 146. 



Fig. 3.— Sporangia (?) of sea weeds. Mag. ^'j°.— From Div. 16, St. .John group. See p. 146. 



Plate VII. 



Fig. l.—Monadites globulosus, n. gen. et sp., la, Group in a spicular network. Mag. V". — 16, Similar organism raceuied 

 (perhaps recent). Mag. Y. — From Div. 1, Basal series at Caton's Island. See p. 14T. 



Fig. 2. — MonadiUs pyriformis, n. sp.— 2a, Single example.— 26, Budded (?) example. Both mag- '"-. From Div. 1, 

 Basal series, Caton's Island. See p. 147. 



Fig. 3. — Monadites urcei/orviis, n. sp., Mag. y. — From Div. 1, Basal series, Caton's Island. See p. 147. 



Fig. 4. — Eadiolariles oralis, n. gen. etsp., Mag Y — From Div. 1, Basal series, Caton's Lsland. See p. 118. 



Fig. 5. — PlocoscypMa (?) peraniiqua, n. sp., — 5a, Section of the sponge, natural size ; to show the form of the 



cavities.— 56, Cuticle of loculus showing oscules. Mag. -\". All from Div. 1, Basal series, Caton's Island. 



See p. 148. 

 Fig. 0. — Astrochidia (?) elongata, n. sp., Nat. size. From Band 6, St. John Group. See p«148. 

 Fig. T.—Anrodadia (?) digans, n. sp., Nat. size. From Band 6, St. John Group. See p. 14î>. 

 Fig. S. — .'l.s(roc/od(n (?) riryuloiden, u. sp., — Sa, Part of large branch, natural size.— 86, Same enlarged ',". — Sc, Same 



enlarged to show sjiherules. From Band 6, Div. 1, St. John Group. See p. 149. 

 Fig. 'J. — Dichoplectdla irregularis, n. gen. et sp. — 9'(, Part of skeleton showing dichotomous spicules. Mag. -j". — 



96, Part of skeleton showing long slender sjiicules. Mag. "-". From Div. 2, Basal series, Caton's Island. 



See p. 149. 

 Fig. 10. — Hijalosldia minima, n. sp., Mag. -j". From Div. 1, Basal series, Caton's Island. Sec p. 150. 



Fig. 11 — Plaly.ioknitcs aiitiquissimu.'!, Eichw. — lie. Interior of one half, showing the joints. Mag. ; — 116, Transverse 

 section of the fossil, Mag. j.— lie. Transverse section of a flattened specimen. Mag. j. All from Div. 2, 

 Basal series, Caton's Island. See p. 150. 



Fjc;. 12. — Lcperdilia renlricosa, n. sp. — 12f(, Interior of right valve, natural size. — 126, Longitudinal section of same. 

 — 12c, Transverse section of same. — l'2d, Surface of the crust enlarged to show the sculpture. From 

 Band 6' in the St. John Group. See p. 159. 



Sec. IV, 18S9. 21. 



