Thompson.— Metamorphoses of Hermit Crab. 
PLATE 10. 
Roman numerals indicate thoracic limbs and abdominal segments. 
Abbreviations Common to all Figures. 
car — sinus of carapace. 
desc m —descending muscle. 
en m — enveloping muscles. 
ext — extensor muscles. 
Hex — flexor muscles. 
g — gonad. 
gang — ganglia. 
hit — achitinous gut. 
lat m — lateralis muscles. 
ten m — loop-enveloping muscles. 
I m — loop muscles. 
I seg a — left segmental artery. 
nc — nerve cord. 
pi m — pleopodal muscles. 
post l — posterior lobe of liver. 
r seg a — right segmental artery. 
st a — sternal artery. 
vent — ventralis muscles. 
x — descending portion of loop muscles. 
x 2 — descending portion of enveloping 
muscles. 
Fig. 59a-f. Muscles of abdomen, glaucothoe, slantingly sagittal; the 1st, 2d, 
3d, 4th, 7th, and 10th, of a series of sections each ten micra thick. 
The transversalis muscles are blackened. 
Fig. 60. Diagram of the flexor muscles of glaucothoe ; lateralis and ventralis 
omitted except where they come in contact with the other muscles. 
Viewed from within. 
Fig. 61. Flexors of Cambarus; series of four sections for comparison with 
sections in figure 59 ; descending, ventralis, and lateralis omitted for 
clearness. 
Fig. 62. Sexual cells, glaucothoe, reversed by compound microscope, sa, pos¬ 
terior aorta. X 370. 
Fig. 63. Sexual cells, sixth stage. See plate 8, figure 42. ms, nuclei of 
mesodermal sheath. X 370. 
Fig. 64a-d. Development of artery b as shown in one individual. 
Example 2, page 165. sa, superior abdominal or artery b. 
Fig. 64a. Dorsal aspect, plotted from sections. X 220. 
Fig. 64b-d. The three successive sections indicated in fig. 64a. X 60. 
Fig. 64b. Showing the outer end of the left segmental artery cut longitudi¬ 
nally, and the right artery in cross section. 
Fig. 64c. Showing the tips of the segmental arteries passing into the pleo¬ 
podal muscles on each side. 
Fig. 64d. Showing the tips of the segmental arteries in the muscles and 
artery b' running beneath the extensors before it dips toward the 
flexors. 
