42 



BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Table 5. — Time of spawning of the lobster in Vineyard Sound and vicinity in 1891. 



No. 



11,30 



11-13 



14-16 



17-21 



22 



23 



24 



25,26 



27 



28 



29, 30 



31 



32 



33 



34 



35, 36 



37, 38 



Locality. 



Gay Head . . 



do 



Menemsha. 



....do 



do 



Date of 

 capture. 



July 



July 



July 



do 



do 



Gay Head ; July 



...'.do do . 



do do . 



Menemsha Aug. 



do ]...do . 



do j...do . 



do ! ... do . 



do ...do . 



Woods Hole Harbor . . Aug. 



Gay Head j Aug. 



do . . .do . 



do .do . 



do '.. -do . 



Menemsha : Aug. 



Woods Hole Harbor . . ' Aug. 



do , Aug. 



Gay Head ! Au, 



.do 

 .do 

 .do 



Aug. 

 do 

 do 



Stage of development. 



Age of embryo. 



Yolk segmentation 



Close oi' yolk segmentation 



Invagination 



Late stage with eye pigment 



Close of yolk segmentation 



do... T. 



Eye pigment formed 



Egg nauplius 



Invagination (?) 



do 



Close of yolk segmentation 



Egg nauplius 



Late stage, eye pigment conspicuous 



Before formation of eye pigment 



Invagination 



Thoracic abdominal plate 



Egg nauplius 



Post-nauplius stage 



Early egg nauplius 



Invagination 



Egg nauplius, late stage 



Eggs free in ripe ovary 



Egg nauplius, late stage 



Eye pigment forms large, nearly oval spot 

 Egg nauplius 



1 | days. 



3 clay's.. 



4 days . - 

 29 days. 

 3 days . . 

 3 days . . 

 27 days. 

 15 days. 

 4days . . 

 4days.. 

 3 day s . . 

 15 days. 

 30days. 

 25 days. 

 4days.. 

 8days.. 



15 days. 

 20 days. 

 10 days. 

 4 days.. 



16 days. 



18 days. 

 42 days. 

 15 days. 



Date of 



extrusion 



of eggs. 



July 17 

 July 20 

 July 24 

 June 29 

 July 25 

 July 26 

 July 2 

 Julv 14 

 Aug. 1 



Do. 

 Aug. 2 

 July 21 

 July 6 

 July 14 

 Aug. 7 

 Aug. 3 

 July 27 

 July 22 

 Aug. 2 

 Aug. 8 

 Aug. 2 



Aug. 3 

 July 10 

 Aug. 6 



Table 6. — Time of spawning of the lobster in Vineyard Sound in 1892 and 1893. 



No. 



l 



2 

 3 

 4 

 5 

 6 

 7 

 8 



1-3 



4 



Locality. 



"Woods Hole Harbor 

 do 



.do 



.do 



.do 



.do. 



.do 



.do 



Menemsha 



Woods Hole Ha r 



.do 

 .do. 



Date ot 

 capture. 



1892. 

 July 29 

 July 3U 

 Aug. 1 



...do 



Aug. 3 

 ...do.... 

 ...do .... 

 Aug. 6 



1893. 

 Julv 25 

 Aug. 11 



Aug. 15 

 ...do.... 



Stage of development. 



Invagination 



Egg nauplius 



Beginning of yolk segmentation. 



Invagination 



Close of yolk segmentation 



Post-nauplius stage 



Before eye pigment is formed. . . . 

 Yolkunsegmented 



New eggs : stage not determined 



Eggs laid in aquarium at United States 

 Eish Commission station. 



Close of yolk segmentation 



Eive pairs of appendages behind mandi- 

 bles; no eye pigment. 



Age of embryo. 



4 days . . 



1 5 days 



1£ days 



4 days 



3 days 



20 days 



26 days 



About 1 day . . 



Date of 



extrusion 



of eggs. 



July 25 

 July 15 

 July 31 

 July 28 

 July 31 

 July 14 

 July 8 

 Aug. 5 



About 

 Aug. 10 



3 days ' Aug. 12 



23 days July 23 



Table 7. — Variation in time of spawning of lobsters in Vineyard Sound and vicinity in the years 1889-93. 



Period of spawning. 



1889. 



1890. 



1891. 



1892. 



1893. 



Total. 

















16-30 



5 

 14 



1 



11 

 62 

 13 



1 



6 



12 



18 



1 







6 

 34 

 80 

 34 



1 



July 1-15 



3 

 4 

 1 



1 

 2 





16 31 















20 



86 



38 



8 



3 



155 





The data afforded by the preceding tables lead us to conclude that the summer 

 eggs are produced in this region during a period of about nine weeks, extending from 

 the middle of June to the middle or last of August, the largest number being laid 



