NO 



LINDSTRÖM, VISUAL ORGANS OF TI I K TKILOBITES. 



Pl. III. 



Bumastus n. sp. p. 47. 

 Fig. 1. Hypostoma 'i. Specimen AY. From Wisby, 

 Norderstrand. 



>. Its left macula 12 i. 



Bumastus n. sp. (different from the preceding) p. 47. 



Fig. .'!. Hypostoma 4 i. Spec. AT from Wisby, Norder- 

 strand. 

 4. Vertical scction of the macula a in its longest axis. 

 .">. A portion of the cephalic eye, t he facets verv low. 



Calymmene intermedia LlNDSTR. p. 4«. 

 Fig. 0. Hypostoma 'i. Spec IiG from Gotland. 

 7. The left macula 12 i. 



Calymmene tuberculata BRUNNICH p. 48. 



Fig. 8. The inside of the hypostoma s , i. Spec. HA 

 from Gotland. 

 '.K Horizontal section near the surface, seen from 

 the inside 20 i. 



Chasmops macroura ( ? ) p. 49. 

 Fig. K». The left macula, cast of the inside '- i. 

 Rostock. 



Chirurus glaber Ang. p. 50. 

 Fig. 11. A portion of the surface of the cephalic eye 

 12 /i. From Dalecarlia. 



Chirurus ornatus Dalm. p. 5o. 

 Fig. 12. Horizontal section of a cephalic eye near the 

 surface 60 /i. 



Vertical section of the same, 20 i at the in- 

 teriör margin. A line added to show the 

 supposed size of the fragmentary lenses. 

 The left macula of the hypostoma '- i. 

 From Östergötland, Westana. 



13. 



I I 



Chirurus spinulosus NlECSZKOWSKI p. 51. 



Fig. 15. The riglit macula of the hypostoma from the 

 inside 12 i. Helongs to Dr. G. Holm. from 

 Esthonia, Kuckers C 2 . 



Chirurus sp. p. 51. 

 Fig. Hl. The left hypostomic macula 12 /i. Oland, 

 Brimsby kanal. 



Cyrtometopus clavifrons Dalm. p. 49. 

 Fig. 17 '& 18. Horizontal sections of cephalic eyes 6 %. 



19. Vertical sections f cephalic eyes and a part 

 of the cheek 2 " t. 



20. A highly magnitied portion of the eye in 

 vertical section ''" i. 



21. Hypostoma, :i i the anterior wings completcd 

 ätter ahother specimen. From Östergötland. 



Cyphaspis elegantula ANGELIN p. 52. 

 Fig. '-'2 & 23. Horizontal and vertical sections of ce- 

 phalic eyes ,; " i. Diameter of facets 0,<>:; inni. 

 > 24 & 25. Hypostomas from the front side and 

 in side view s i. Upper Silurian, Gotland. 



Ctenopyge pecten SALTER p. 29. 

 Fig. 26. The head shield, the free cheeks added from 

 Other specimens ' i. 

 •27. A free cheek, viewed withoul foreshortening, 

 as in its natural position ' t. Alumscbists 

 nf Andrarum, Scania. 



Ctenopyge n. sp. (Linnarsson, Geol. För. Förliandl. 



1880, pl. VI, tigs. 14, 15) p. 20. 

 Fig. 28. A free cheek ' ; i. 

 » 29. Surface of the eyes, near the suture 30 , i. 

 .'50. The same next the free cheek 30 /i. Andrarum. 



Sphserophthalmus alatus ANG. p. 29. 

 Fig. 31. The head shield; the free cheeks have bcen 

 added * i. 

 » 32. A free cheek without foreshortening s /i. 

 33 & 34. Horizontal and vertical sections of ce- 

 phalic eyes 100 /i. The cornea nearly 0,oi mm. 

 in thickness. Andrarum. 



Peltura scarabseoides Wahlenb. p. 29. 



Fig. 35. The head shield; the free cheeks added - i. 



■» 36. A free cheek, not foreshortcned V 1 - ' 



37. A cast of the inside of the cephalic eye 20 /i. 



38. A portion of the cephalic eye from the inside' 1 " i. 



39. A portion of the same in transmitted light " J " 'i. 



40. Vertical section of au eye 10 %. The rock on 



41. 



42. 



Vertical section of an eye 



the inside. 



A similar one passing through two rows of 



lenses, the one behind the other. The rock 



on the outside 10 °, i. 



A hypostoma 6 /i. Andrarum. 



Dalmanites imbricatulus Angelin p. 53. 

 Fig. 43. The cephalic eye near the interiör margin 2 " i. 

 4 4. Vertical section of the same and a portion of 

 the free cheek 6 %. The lenscs are almost 

 contiguous and the interspace between them 

 is formed by the cominon test of the body, 

 which is perforated by longitudinal tubes. 

 Dalmanites obtusus 1.INDSTR. p. 53. 

 Fig. 4"). Horizontal section of cephalic eye near the 

 interiör margin :1 " i. 

 4(1, Vertical section, the interspaces being in this 

 wider than in the preceding 60 /i. From Gotland. 

 Dalmanites vulgaris SALTEK p. 54. 

 Fig. 47. Fart of the cephalic eye near the interiör 

 margin 2 "/i. 

 4«. Horizontal section near the surface at the in- 

 teriör margin "° i. 

 49. A tangential section, so that the interiör part 

 is below the lenses where the peculiar radiat- 

 ing strueture is seen in horizontal section :i " i. 

 "iii. Vertical section of a small specimen, tibrous 

 appendices below the lenses :i " i. 

 Hypostoma -. i. 



The riglit. macula 12 i. English specimens 

 from Dudley, Shropshire. 

 Dysplanus centrotus Dalman p. 55. 

 53 & 54. Horizontal and vertical sections of an 

 eye 60 i. 

 Hypostoma 8 /i. 



The anterior wing of the hypostoma seen in 

 foreshortening' 1 i. Specimen AX from Westana, 

 Östergötland. 

 Dysplanus ladogensis HOLM p. 55. 

 Fig. 57. Hypostoma 3 /i. 

 » 58. The same, scen Ironi the side 

 Al from Östergötland. 



Fig. 



51 

 52 



55. 

 56. 





i. Specimen 





