IN THE GENUS ANTHOPHORABIA. 165 



EXPLANATION OF THE EIGURES. 



Tab. X. 



Fig. 10. Front view of the head of the male Anthophorabia fasciata, highly magnified, and seen by trans- 

 mitted light, a. The antenna, formed of ten joints, 1 to 10. b. The lateral, and c. the ver- 

 tical ocelli, d. The rudimentary brain, d d. The optic nerve, e. The labrum. f. The man- 

 dibles, g. The labium, h. The maxillary palpi, i. The extensor, k, the flexor (?), and 1 1, the 

 adductors of the antenna, m. The extensor, and n. the flexor of the distal joints of the an- 

 tenna, o. The antennal nerve, p. The oesophageal ring. q. The suboesophageal ganglion, pro- 

 tected by r. the basilar apophyses of the head. s. The sub-epicranial apophyses, to which are 

 attached, on their inner surface, the extensor of the antenna i, and on their external part of 

 t. the extensor of the mandible, u. The flexor of the mandible, v. Extensor of the maxilla. 



Fig. 11. A young Astacus pellucidus from the caves of Kentucky, showing the presence of the eye (b). 



Fig. 12. Dissection of the cephalic portion of the young Astacus, by removal of the upper surface of the 

 head, to show the distribution of optic nerves from the brain (d) to the eyes (b). 



Fig. 13. The eye, &c, highly magnified, a. Antennal nerves, b. The cornea, c. Brain, d d. Optic nerve. 



Fig. 14. Surface of the apex of the cornea, showing the rudimentary corneales. 



Fig. 15. The eye of Tallitrus locusta, showing distinct convex corneales; for comparison with Astacm. 



VOL. XXI. 



