X 
ILLUSTRATIONS. 
Plate 
No. Page. 
•53. (Fig. 250) Surface view of Embryo in invagination stage 252 
54. (Fig. 251) Part, of transverse section through area of invagination. (Fig. 252) Surface view of Embryo in region 
of invaginate area. (Fig. 253) Part, of longitudinal section of intestine of Embryo in a late stage of devel- 
opment. (Fig. 254) Part of transverse section through invaginate area of an earlier stage than last. 
(Fig. 255) Part of longitudinal section through area of invagination. (Fig. 256) Concretion from intes- 
tine of an Embryo which was nearly ready to hatch 252 
Cut 1. Curve of fecundity of the Lobster 52 
Cut 2. Curve of fecundity of the Lobster 53 
Cut 3. Curve showing the relative fecundity of 352 Lobsters, each 10 inches long 54 
Cut 4 (Plate A). Part of transverse section of exopodite of pleopod of Female Lobster (the cuticle removed), 
showing the distribution of the cement glands 77 
Cut 5 (Plate A). Diagram of vertical section through shin, showing a tegumental gland in sections, and its 
duct opening to the exterior 77 
Cut 6 (Plate B). Left cheliped of Lobster, seen from the dorsal side 86 
Cut 7 (Plate B). Transverse sections of cheliped 86 
Cut 8 (Plate C). Xhe"gastrolith of a Lobster nearly ready to molt, removed from the wall of the stomach 89 
Cut 9 (Plate C). Diagrammatic section through the wall of the stomach of a molting Lobster, cutting 
gastrolith 89 
Cut 10 (Plate C). Section of the deciduous portion of old cuticular lining of stomach overlying gastrolith 89 
Cut 11 (Plate C). Section of gastrolithic sac from wall of stomach underlying gastrolith, as it appears while 
the latter is still in place in the stomach 89 
Cut 12 (Plate D). First left pereiopod of adult Lobster, seen from in front, showing anterior border at base of 
limb ; . 100 
Cut 13 ( Plate D) . Basal portion of first left pereiopod of adult Lobster, from under side 100 
Cut 14 (Plate D) . Second left pereiopod of Female, 10 inches long, seen from under side 100 
Cut 15. Part of first cheliped of fourth Larva, showing the base of the limb and distinct articulation between 
the second and third joints 102 
Cut 16 (Plate E). Double right cutting-claw of Female Lobster 147 
Cut 17 (Plate E). Double right cutting-claw of the same Lobster, seen from above 147 
Cut 18. From transverse section of a part of ovary of Lobster, hardened with ventral side uppermost, to show 
the effect of gravity upon the nucleolus 154 
Cut 19. From transverse section of a part of same ovary, hardened with dorsal side uppermost, to show effect 
of gravity upon the nucleolus 154 
Cut 20 (Plate F). Egg Embryo, showing membranes abnormally distended after prolonged immersion in picro- 
nitrio acid 205 
Cut 21 (Plate F). Projection of an Egg with ]5 yollr-cells, all near the surface or approaching it 205 
Cut 22 (Plate F). Projection of an Egg with 28 yolk-cells, 3 in karyokinesis, mostly near the surface 205 
Cut 23 (Plate G). Egg with about 32 yolk segments present, seen from vegetative pole 206 
Cut 24 (Plate Gr). Reverse side of same Egg, showing divided nuclei at the animal pole 206 
Cut 25 (Plate G-) . Surface view of Embryo 8 days old in invagination stage, showing pit at surface, embryonic 
area, and mass of in-wandering cells which penetrate deeply into the yolk 206 
Cut 26 (Plate Gr). Surface view of Egg in invagination stage, pit transversely elongated, showing tendency to 
become horseshoe shaped 206 
Cut 27 (Plate H). Surface view of Embryo, showing buds of first pair of antennae and clouds of in-wandering 
cells - 208 
Cut 28 (Plate H). Surface view of Embryo, showing buds of first pair of antennae and of mandibles 208 
Cut 29 (Plate H) . Surface view of early Egg-nauplius Embryo, showing buds of the first and second antennae 
and the mandibles 208 
Cut 30 (Plate H). Surface view of Egg-nauplius, second antennas bifid; labrum and thoracic abdominal fold 
present 208 
Cut 31 (Plate I). Surface view of Egg-nauplius, showing thoracic abdominal fold 209 
Cut 32 (Plate I). Surface view of Egg-nauplius, showing parts much more concentrated than in earlier stages. 209 
Cut 33 (Plate I). Surface view of Embryo with first maxillae budded 209 
Cut 34 (Plate I). Surface view of Embryo, showing live pairs of post-mandibular appendages 209 
Cut 35 (Plate J). Surface view of Embryo with eye-pigment in form of crescent, as seen from the surface 210 
Cut 36 (Plate J). Embryo 61 days old: area of eye-pigment semicircular; telsou behind brain 210 
Cut 37 (Plate J). Embryo 122 days old; area of eye-pigment rounded or irregularly oval in outline 210 
Cut 38 (Plate J). Embryo 211 days old ; area of eye-pigment irregular, somewhat oval or rounded in outline. . 210 
Cut 39. Median longitudinal section through abnormal Embryo 215 
Cut 40. Sagittal section through abnormal Embryo 215 
55. Fish-cultural Apparatus used at Freising 320 
56. Chart of Mobile Bay, Alabama, showing location of Natural Oyster Beds 325 
57. Shells of Specimens of cultivated Oysters from Plant Beds at mouth of Fowl River, Alabama 340 
58. Shell of Oyster from Plant Beds at mouth of Fowl River, Alabama 340 
59. Bunch of Oysters from Great Point Clear Reef, showing growth of Mussels and Barnacles 340 
60. Shells of Oyster's from Fish River Reef 340 
