OF THE AMERICAN KING-CRAB. 505 
Fig. 3. Cnemion. 
9. Propes. 
6. Dactylus. 
Fig. 4. Maxilliped (7th cephaletral limb). 
1-5, as in fig. 3. 
6. Lamelligerous joint. 
7. Chelate extremity. " 
Fig. 5. Mandibula (3rd cephaletral limb) dissected for the muscles. 
. Flagellum. 
Cnemial appendage. 
Terminal lamellz. 
Extensor basis maxillæ. 
Flexor basis. 
Merional entapophysis. 
Flexor merioni cnemiique. 
Propedal entapophysis. 
Flexor propedis. 
Flexor dactyli. 
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3 
Q SN R 9 oe ssp 
PLATE XXXVIII. 
Fig. 1. Nervous system, from the lower or ventral aspect. 
A”. Inferior concave surface of cephaletron. 
B'. Infero-lateral surface, p" Infero-median surface of thoracetron. 
n xv. Nerve of anal segment. | 
(The other letters and figures as in Plate XXXVII.) 
Fig. 2. Compound eye and terminations of ocular nerve, from the dorsal aspect: magnified 6 diameters. 
d. Dorsal branch and divisions of ocular nerve. 
v. Ventral branch and divisions of ocular nerve. 
Fig. 3. Compound eye of a Trilobite (Phacops conophthalmus) : magnified 3 diameters. 
Fig. 4. Portion of the same compound eye: magnified 10 diameters. 
Fig. 5. Entosternon and attached parts of muscles. (After Van der Hoeven, op. cit.). 
Fig. 6. Chief parts of ovarium, oviducts, and opercular plate (upper or inner surface). 
m". Muscles of operculum. 
0, 0. Oviducts. 
p. Oviducal outlets. 
q. Postero-median lobe of ovary. 
q*. Antero-median lobe of ovary. 
q”. Antero-lateral loops and branches. 
q*. Anterior branches. 
q**. Postero-lateral cephaletral branches. 
r. Articular surface of opercular plate. 
2. Second joint of opercular plate. 
3. Third joint of opercular plate. 
4. Appendages of opercular plate. 
Fig. 7. Section of terminal part of oviducts. (After Van der Hoeven, op. cit.) 
a. Oviduct; à, anterior labium ; c, portion of opercular plate. 
Fig. 8. Portion of opercular plate with terminations of the sperm-ducts, p. (After Van der Hoeven, op. cit.) 
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