A72 TABLE SHOWING NUMERICAL CORRESPONDENCE 
ARACHNIDA. CRUSTACEA. 
Somites. | ——— ~~ = 
ScorPIONIDA. MEROSTOMATA, PYCNOGONIDA. TRILOBITA. LEPTOSTRACA. 
1 Eyes Eyes Eyes Eyes Stalked eyes 
2 Rostrum — — Feelers (Triarth-- Antennules 
rus) Beecher (1) 
3 Cheliceree Chelicere Chelicerze ‘lst biramous head Antenne 
limbs 
4 | [Vestigial seg- — Palpi 2nd if Mandibles 
ment in Epeira]. | 
Lendl (22) | 
5 Pedipalps 1st simple limbs | Ovigerous legs 3rd = Maxillule 
6 Ist legs 2nd 3 Ist legs, 2 4th s Maxille 
7 Sud; 3rd 4 Indy, iT 2 1st trunk-limbs 1st thoracic limbs 
8 3rd » 4th ” 3rd ” 3 2 2nd » 2nd ” 
9 Aids a: Paddle-limbs 4th, ,~ & .9<) ard 2 3rd y 
10 Sternum (?). Pre- Chilaria (Abdomen 4th “3 4th am 
genital seoment. reduced and 
| Brauer (2) condensed) 
11 Genital oper- Genital oper- — 5th ; 5th “5 
culum, ¢ 9?! culum, ¢ 9 | 
12 Pectines 1st gill-plates -- 6th 33 6th 22 
| 
13 Ist lung-books | 2nd a = 7th 35 ‘7th - 
14. Sd -- 3rd i, = Sth 5 8th ae: 
15 3rd 3 4th 3 — 9th Fs Ist pleopods 
16 ee Sth ~~, = 10th ys and” 
17 7th abdominal | 7th abdominal = 1lth eS ard. ia 
segment segment 
18 Ist tail-segment | 1st tail-segment — 12th ne ‘4th S 
19 2nd = 2nd zs — 13th Fe 5th Ms 
20 | 8rd . 3rd be cs 14th ie 6th tag 
| 
21 4th = 4th a, = 15th 3 Limbless seg- 
(Number of trunk ment 
segments highly 
variable) 
22 Anal segment | Anal segment | Anal segment (?)) Analsegment | Anal segment 
Furea 
Sting 
Telson 
Telson 
1 The signs g ? indicate the 
