578 GEOLOGICAL SURVEY OF THE TERRITORIES. 



EXPLANATION OF PLATE XXXII. 



Fig. 1. Apus lucasanus Pack. Section tlirougli tlie body, with the intestine removed 

 md, inamlihle ; anP,ant^, let and 2d antennas; leg^, first pair of legs; br, 

 flabelhim ; oi\ ovary ; ng, gangliouic chain. 



Fig. 2. Transverse section through the body at the 7th or 8th pair of feet, the 

 shell removed, mu8, dorso-ventral adductors of the feet, crossed by the ad- 

 ductors of the exites; ht, heart; int, intestine; ov, ovary; «. g', ventral 

 ganglion; en^-en^, endites; br, gill; Jl, iiabellum; x, eubapical lobe. 



Fig. 2a, Ifit antenna; 2b, 2d antenna; 2c, the extremity of 2d antenna, Tvith 4 bead- 

 like joints, showing the three imperfect joints, the third ending in a monili- 

 form portion. 



Fig. 3. Maxillipede with the gill (br) and single endite. 



Fig. 4, 4a, dorsal and lateral view of the brain of the European Apm cancriformis;^ hr, 

 brain; com, commissure to subcesophageal ganglion; g op, optic gauglioti; 

 00, ocellus ; oes, end of oesophagus. 



Fig. 5. Brain and part of A^entral cord of Apus cancriformis ; oc, nerve tto ocelli ; awi', 

 ant^, first and second autennal nerves ; G', oesophageal ; G", mandibular 

 ganglion, sending ofi" three mandibular nerves (n md); d, descending oeso- 

 phageal nerve; h, unpaired or lower oesophageal ganglion; oes, nerve pass- 

 ing to the muscles of the oesopliagus. 



Fig. 6. Heart of Apus cancriformis. 



Fig. 7. Apus lovgicatidatus, portion of embryonic membrane lying next to the chorion, 

 and supposed to represent the amnion in Limulus ; the nuclei in many of 

 the cells have become absorbed. 



Fig. 8. An egg of the same, showing the cellular nature of the amnion. 



Fig. 8a. A portion of the same amnion seen sideways of the egg. 

 Fig. 1 drawn under the author's direction by J. S. Kiugsley; Figs. 4, 4a, 5, and 6, 



copied from Zaddach; the remainder drawn with the camera by the author. 



