66 
GROUP OF SPECIES WITH 23-33 AXIAL JOINTS IN PYGIDIUM. 
Encrinurus punctatus.. ........(Hntire) ......23-30 axial joints, 9 pleurae. 
Stockesiq Mic Coymesseeesee (BERS) coasoc 28 He HS tai93 & 
——Trentouensis, Walc........ (QW) me seopaden: 23 oe & 6) oa 
Barrandei, DeKon ........ (head & tail) 25-26 ‘ M3 9 % 
multi-segmentatus, Portl (tail) ........... 32 i oe O=LOme 
SPAMS JABS) Cen coceoadecace (tail).....not known ‘‘ “To + 
tuburculosus, Collie se co 8 uk 
——deltoides, Shum............ i Z oh bi 7 Bt 
GROUP OF SPECIES WITH 20 AXIAL JOINTS IN PYGIDIUM. 
Encrinurus sexcostatus, Salter (Entire) ........ 20 axial joints, 6 pleurae. 
——Aniericanus, Voegd.......... (tall) racy aces 20 ie ss 5-6“ 
——prnatus, H. W....(tail, Ohio specimen) ...20 “ so 7-8 
GROUP OF SPECIES WITH 16-18 JOINTS TO RYGIDIUM. 
Encrinurus nereus, Hall........ (tall ey paces 18 axial joints, 8-9 pleurae. 
IDesevoyls MONEE oo oncpoesceo (GBnitine)) eee: 18 uk “f 6 we 
—Threcheri, Foerste.......... (taullics tee ok T8=20 “ “7-8 we 
raricostatus, Wale.......... (fail) sAete.c.. 16 oi 4 6 ee 
vanniwlus, Clarke... (GE ntine) eee. 14-16 “ “TG = 
Weiss, Melero gconconooosqoueee (Eimtine)) pense: 14 = i 8 $ 
sehisticola,, Lorna) 2-----e- (Batire) eee T4-16 “ “7-8 “f 
Bowningi, Foerste......... (Hntire)........ 18 Oe “30 ae 
Encrinurus vigilans, Hall..... (Eaabine))ieneeses 18 axial joints, 9 pleurae. 
GROUP OF SPECIES WITH 9-I5 AXIAL JOINTS IN PYGIDIUM. 
Encrinurus variolaris, Brong. (Entire)........ g-10 axial joints, 7 pleurae. 
axpansus, Haswelll......... (@Euitine) See... I4 =e aes u 
falas need cyeererre: senece (Entire)........ I2-14 ‘' “5-6 * 
OLONSTUIS,, FANON S  canscscs aoondel pene ccscoe 12 a = 46) 7: 
Indianensis, Collie ...(head and tail)...15 os “* Tome 
The species may be grouped as follows: 
ENCRINURUS. 
1. Enerinurus punctatus, Stockesi, Trentonensis, Barrandei. 
2. EE. vigilans, Seebachi. 
E. sexcostatus, deltoides. 
oy) 
4. E. multi-segmentatus, striatus. 
5. E. Nereus, ornatus, Egani, Threcheri, Americanus. 
6. EE. raricostatus, vannulus. 
CRYPTONYMUS. 
7. KE. variolaris, expansus, obtusus, levis. 
8. Bowningi. 
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