4 BRITISH FOSSIL CRUSTACEA. 
ARRANGEMENT AND NOMENCLATURE OF THE SEGMENTS OR 
I. SremEnts or THE Heap (Ldwards, 
Bell, &c. &c.) 
II. 1. Bearing the Eyes. 
II. Ds S », Antennules, or Internal 
Antenne. 
ill. 3), ; » External Antenne. 
IV. 4. », Mandibles. 
V. 5. af » Ist Maxille. 
VI. 6. ae ay PAiGl 
VII. de - », Maxillipeds. 
II. SrGments or THE THORAX. 
VIII. 1. Bearing the 2nd Maxillipeds. 
IX. UBS », ord + 
X. 3. 
XI. | ie furnished with organs of 
XII 5. prehension or Ambulatory or 
XIII 6. Natatory appendages. 
XIV. f: 
III. ABDoMEN. 
be 
=< 
_— 
wm 0 B= 
feet, or false abdominal feet ; 
rudimentary in the Brachyura ; 
| branchiferous in Squilla ; ovige- 
XIX. 5 rous in the females of nearly all 
genera. 
G | Usually furnished with swimming 
XX: 6 
CAM ie 
| dages.! 
Caudal segment destitute of appen- 
(According to the 
I. SEGMENTS OF THE CEPHALOTHORAX 
(Dana).” 
E 1. Ophthalmic Segment. 
AE 2. Ist Antennary _,, 
Ill. S2ndis,; 3 
IV. 4. Mandibular “6 
V. 5 
Vi 6. 
VII. 7. 
5 14th S : illary, 
VHL 8. Sth to 14 EOE Maxillary 
and Podal, 10 pairs. 
1X. 9 
X. 10. 
XE 1] 
XII. 12 
XIII. 3 
XIV. 14 
I]. ABDOMEN. 
XV). 15 
XVI. 16 
eee 17. | 15th to 19th Segment, bearing 
: ue abdominal feet. 
XIX. | 19. 
| 
XX. | 20. Segment, bearing caudal abdomi- 
| nal appendages, | pair. 
| 
XXI. | 2ist. Or caudal segment without ap- 
pendages. 
1 Prof. Bell considers the extremely minute and moveable 
points attached to the extremity of this segment in Palemon 
serratus to be a pair of rudimentary appendages.—[See 
Introduction to ‘ Bell’s Hist, British Stalk-eyed Crustacea,’ 
p. XX, 1853. | 
2 “Crustacea have a cephalothorax, but not a head”— 
Dana, on Homologies of Crustacea.—‘ United States Explg. 
Expedition,’ Crustacea, yol, xili, p. 21, 1852. 
