﻿PLATE IX. 



IILUSTRATIONS FROM RECENT CRUSTACEA. 



Fig. 

 1. Under side of Limulus polyphcemus, ?, from eastern shores of North America. One third natural 

 size. Drawn from a dried specimen. 



1. The cephalic shield bearing the sessile eyes upon 



its upper surface. (The eyes, of course, cannot 

 be seen in this view.) 



2. Inner or first antennae or antennules. 



3. Second antennas. 



4. Mandibles. 



5. First maxillae. 



6. Second maxillae. 



7. Maxillipeds. 



8. Operculum (covering reproductive organs). 

 9 — 13. Branchial plates. 



14. Telson. 



1 a. Modified antenna of male Limtdus polyphcemus. 

 1. Basal joint, with its palpus, p. 



1 6. A detached maxilla of same, showing the palpus, p. 



1 c. The operculum of Limulus polyphcemus, detached. The position of the ovaries is indicated by the 

 dotted lines at a ; d, d, detached articulated appendages, which in Pterygotus are welded together 

 and form one coalesced median appendage, but remain bilobed at their extremity in Eurypterus. 



2. Calanus curtus, Dana, $ , ' United States Exploring Expedition,' Crustacea — Cyclopoidea, vol. xiv, 



part ii, p. 1059, Atlas, plate lxxii, fig. 10. Sooloo Sea, west of Panay, and Straits of Banca, 

 east of Sumatra. 



3. Corycceus crassiusculus, Dana, $> , 'United States Exploring Expedition,' Crustacea — Cyclopoidea, 



part ii, vol. xiv, p. 1214, Atlas, plate Ixxxv, fig. 7. Soloo Sea, west of the Island of Panay. 



4. Sapphirina ovato-lanceolata, ? , Dana, ' United States Exploring Expedition,' Crustacea — Cyclopoidea, 



part ii, vol. xiv, p. 1251, Atlas, plate lxxxvii, fig. 15. Atlantic, off the harbour of Rio Janeiro, 

 lat. 23° S. ; long., 41° West. 



5. Canthocamptus linearis, $ , Dana, ' United States Exploring Expedition,' Crustacea — Cyclopoidea, 



part ii, vol. xiv, p. 1 188, Atlas, plate lxxxiii, fig. 9 a. From the sea, among the Fejee Islands. 



6. Larva, or Zoea, of Carcinus Mcenas, Penn., immediately as it quits the ovum. 



7. Larva, or Zoea of ditto, after the first moult. 



Figs. 6 and 7 are copied from Mr. C. Spence Bate's paper on the " Development of Decapod Crustacea,' 

 Phil. Trans., 1858, p. 589, plate xl, figs, a and B. 



1. The eye. 



2. The anterior antenna. 



3. Posterior antenna. 



4. Mandibles. 



5. Anterior maxilla. 



6. Posterior maxilla. 



8. Swimming-foot of Polybius Henslowi. 



8. Anterior gnathopoda. 



9. Posterior gnathopoda. 



10. Rudiments of pereiopoda, or walking-legs. 



16. Indications of sexual character ? 



21. Telson. 



