BRITISH AVONIAN CONODONT FAUNAS 159 
LectotyPeE (here selected). The original of Branson & Mehl : 1934, 206 ; Pl. 15, 
fig. 6 only, University of Missouri C 365-5. 
MATERIAL. 672 specimens : figured, X 264, X 263. 
Rance. North Crop KL 1-ZLA 33, Avon Gorge K 3-C 7. 
DescripTIon. The anterior denticle is tall and narrows gradually to a pointed 
extremity. It is produced aborally into an aboral process. The posterior bar, which 
is straight or gently down-curved, is also deflected through 45° and slightly twisted. 
It bears a series of erect laterally compressed denticles, which are either fused or are 
in close proximity. The bar is very long and may possess up to 40 denticles which 
alternate in size. The basal cavity is situated at the junction of the posterior bar and 
the aboral process. It has a flared lip to produce a characteristic flange. 
Remarks. This is one of the most easily recognizable neoprioniodids owing to the 
large aboral process of mature specimens and the cavity flange. Frequently only the 
anterior denticle and cavity flange are preserved. Branson & Mehl (1934 : 206) 
described two co-types of the species Priomodus confluens (Catalogue numbers 
C 365-5, University of Missouri). These appear to represent different species and 
we hereby designate the specimen illustrated in Pl. 15, fig. 6, as the lectotype of 
Neoprioniodus confluens (Branson & Mehl). This is given the same Catalogue 
Number as the other co-type (C 364-5). 
One specimen (PI. 21, figs. Ia—c) shows extreme regularity of dentition and it is 
only tentatively compared with this species. 
Neoprioniodus conjunctus (Gunnell) 
Plate 21, figs. 16a-17b, 20a, b 
1926 Prioniodus sp. B (Roundy) (partim) : 11, Pl. 4, fig. 12 only. 
1931 Prioniodus conjunctus Gunnell : 247, Pl. 29, fig. 7. 
1933 Prioniodus cacti Gunnell : 263, 265, 267, Pl. 31, figs. 4 to 5. 
1933 Prioniodus sp. Gunnell : 264, 267, Pl. 32, fig. 32. 
1941 Prioniodus conjunctus Gunnell ; Ellison : 108-111, 113, 114, Pl. 20, figs. 1-3, 16. 
1941 Prioniodus bulbosus Ellison : 108-111, Pl. 20, figs. 4-7. 
1944 Prioniodus conjunctus Gunnell; E. R. Branson : 327. 
1949 Prioniodus cacti Gunnell ; Youngquist & Downs: 169, Pl. 30, figs. 16, 17. 
1953 Prioniodus inclinatus Hass : 87, Pl. 16, figs. 10-14. 
1956 Neoprioniodus conjunctus (Gunnell) Rhodes & Miiller : 3. 
1957 -Prioniodina bulbosa (Ellison) Bischoff : 46, Pl. 5, fig. 37. 
1960 Neoprioniodus brevis Clarke : 13, 14, Pl. 2, fig. 7. 
1961 Neoprioniodus inclinatus (Hass) Higgins : 220, Pl. 11, fig. 3. 
1962 Neoprioniodus conjunctus (Gunnell) ; Higgins: to, Pl. 1, fig. 2. 
MATERIAL. 7 specimens : figured, X 265, X 267, X 266. 
Rance. North Crop 3D 14/15, Avon Gorge Z 35-C 7. 
DESCRIPTION. The present specimens agree perfectly with Gunnell’s holotype and 
with Ellison’s (1961) descriptions and illustrations. The massive, blade-like anterior 
denticle, with the deep posterior bar consisting of confluent, strong denticles, up to 
about 4 in number, are very conspicuous features of the species. However, the 
