12, 



Pedicellina Americana . 



Pennel Cholmondeley 



Peristome 



Pericardial space il, 



Pinnotheres ostreum. 



Poli 



Polyps 



Potomac River ( ).. 



Premiums for ripe shad 



Probatocephalus ... 



Proposed new methods of 

 caring for artificially im- 

 pregnated eggs 



Propositions laid down by 

 Mobius 



Puysegur, M. of Sissable 



Pycnogonids 



R 



Removal of barges to Wat- 

 son's Island 



Renaud, J 



Reproductive organs dur- 

 ing spawning season . 



Respiration, or aeration of 

 the blood 



Ryder, Prof. J. A . . ! 



Salensky ..... 5, y^^ 



balmo Fontinalis . . . 



iSalmo salar 



" " eggs from 



the U. S. Com'r . . 



Sauerhoff, W. P . . , . 



Saunders, Jno. S . . . . 



"Journal of 

 "Letter " 

 Say, Mr 



Schleswig Holstein . . 



Shad 



Shad success on the Poto- 

 mac 



Shell, changes during 

 growth of the . . . . 



Shell, mechanism of the 



Shell, structure of the . 



Slipper limpets 



Spat, numder of which fix 

 themselves to a single 

 slate 



Spat, Rate of growth of . 



Sponges 21, 



PAGE. 



34 

 77 

 39 

 13 

 24 



76 



SI 



3 



XLVII 

 32 



54 



31 

 21 



34 



XXIV 



79 



10 



X 



90 



LXIII 

 LIII 



LIU 



44 



XXIV 



XXVI 



XXV 



24 

 26 



XVII 

 XVIII 



63 



7 

 8 



37 



62 

 60 



37 



Stentor cocruleus . . 39, 

 " roeselle .... 

 St. Jerome's Creek (cix), 

 ^3,26,30,35,38,47,53,60, 

 "Strike" of the fishermen 

 Structure of heart . . . 

 Systemic heart . , . . . 



PAGE. 



40 

 39 



XLVI I I 

 12 

 12 



Table of catch of shad for 



II years 



Table of amount of fish 

 sold at Washington and 

 Alexandria . ... 

 Table of temperature ob- 

 servations, Washington 

 Table of shad hatching op- 

 erations, Washington . 

 Table of temperature ob- 

 servations at H. de G . 

 Table of hatching opera- 

 tions at H. de G . . . 

 Table of distribution of 



shad • 



Table of distribution of 



Penobscot salmon 

 Table of distribution of L. 



L. salmon 



Table of salmon hatching 



operations 



Table of distribution of 



California salmon . . . 

 Table of distribution of 



trout 



Table of distribution of 



carp 



Table of catch of oysters 



1879— 1880 



Table of maximum and 

 minimum temperature 



Tolle A 



Tunicates 



Turrell, L 



U 



Urosalpinx 



U. S. Coast and Geodetic 



Sujvey 



U. S. Fish Commission . 



Unio 



5, 



IV 



V 

 XX 

 XXI 

 XXXVIII 

 XL 

 XLIII 

 LIV 

 LV 

 LVIII 

 LXII 

 LXIV 

 LXXIV 

 CXII 



74 

 7^ 

 34 



79 



3^ 



67 

 24 

 12 



V 



Valves, difference in shape 

 of 



64 



