PALEONTOLOGIC CONTRIBUTIONS 1 39 



Basilicus: ingens, Barrande, no. 1, pi. 34, fig. 1 (concentric rugae); 

 nobilis, ibid, diagrams, fig. 19, also pi. 31, fig. 1 (concentric rugae); 

 1 o w r o w i , Schmidt, no. 27, Lief. 3, pi. 4, figs. 1, 2, 3, 9;kegelensis, 

 ibid, pi. 5, figs. 1, 4; barrandi, Raymond, no. 17, pi. 1, figs. 4, 5; 

 romi-ngeri, Raymond and Narraway, no. 15, pi. 16, figs. 2, 3. Accord- 

 ing to Schmidt, all species of Basilicus possess the tubercle. 



Bronteus: haidingeri Barrande, no. 1, pi. 46, figs. 32, 34 ; angusti- 

 ceps, pi. 47, fig. 23; palifer, pi. 1, fig. 9, pi. 45, figs. 1, 8; 

 porosus, pi. 48, fig. 23. 



Bumastus: barriensis, Salter, no. 26, pi. 2J, figs, ia, 2; belle- 

 v i 1 1 e n s i.s , Raymond and Narraway, no. 15, pi. 62, fig. 7. 



Ceratopyge: forficula, Moberg and Segerberg,. no. 10, pi. 5, figs. 

 2a, 3 ; 1 a t e 1 i m b a t a , ibid, pi. 5, fig. 6a. 



Cheirurus: niagarensis shows pit on interior mold in place of 

 tubercle (see pi. 34, fig. 9). 



Cryptolithus(Trinucleus auct). The common occurrence of the 

 tubercle in Cryptolithus has been discussed above (p. 128). Besides 

 the species cited by Oehlert, the tubercle is also figured by Barrande 

 (no. 1) in C . o r n a t u s , pi. 2B, fig. 10, pi. 30, figs. 53, 54, 59. 



Cyclopyge: armata Reed, no. 22, pt II, pi. 7, figs. 53, 54, 59. 



Dindymene: frederici augusti, Barrande, no. 1, pi. 43, fig. 24 

 (tubercle on internal cast; suppl. pi. 2, fig. 11). 



Dionide: formes a, Barrande, no. 1, pi. 2B, fig. n, pi. 42, fig. 24; 

 1 a p w o r t h i Reed, no. 22, pt. 1, pi. 4, fig. 1; richardsoni, pi. 4, 

 fig. 3. We have before us a specimen of D. formosa with rudi- 

 mentary lateral eyes (see p. 145), eye lines and the interior mold of the 

 median eye tubercle which appears as a shallow pit, suggesting that as 

 in Cryptolithus the median eye may have possessed a lens. 



Elliptocephala: asaphoides, see p. 137. 



Eo discus (Microdiscus auct.) speciosus (Ford). The author 

 has in the Ford collection specimens which show a distinct parietal eye 

 tubercle' and also scars on the cheeks representing the rudimentary 

 lateral eyes. 



H a r p i d e s : Moberg and Segerberg, no. 10, pi. 5, fig. 1. 



Hemigyraspis: collie an a, Raymond, no. 17, pi. 14, fig. 11. 



Hysterolenus: tornquisti, Westergard, np. 29, pi. 2, fig. 1. 



Illaenus: oriens, Moberg and Segerberg, no. 10, pi. 7, fig. 2a (with 

 crest); cf. oculosus, Reed, no. 22, II, pi. 10, figs. 9, 11. In Museum 

 specimen of I . o x u s with fine tubercle (see pi. 34, fig. 8). 



Isotelus: gigas, Raymond, no. 19, pi. 1, fig. 1. See also our plate 34, 

 figure 6. Schmidt states that Isotelus does not possess the " Nacken- 

 tuberkel " ; it apparently is, as a rule, present only in the immature 

 stages as a tubercle. 



I s o t e 1 o i d e s': w h i t fi e 1 d i, Raymond, no. 17, pi. 14, fig. 1; h o m a 1 o- 

 notoides Raymond and Narraway, no. 15, pi. 16, figs. 10, 11 (see 

 our pi. 36, fig. 1); angusticaudus, Raymond, no. 19, pi. 17, fig. 7. 



Megalaspis: Schmidt (no. 27, Lief. 4, p. 2) states that in Megalaspis 

 the tubercle is so small that it is seen with difficulty and his photographs 

 mostly fail to bring it out. It is specially mentioned of M. larvae 

 (ibid, p. 21), and recognizable in the acuticauda var. typica, 

 ibid, p. 43, fig. 19. In M . h y o r h i n a it is developed into a spine. 



