Fig. 43. The cephalic eye near the inferior margin 20/1. » 44. Vertical section of the same and a portion of the free cheek 60/1. The lenses are almost contiguous and the interspace between them is formed by the common test of the body, which is perforated by longitudinal tubes. =Dalmanites obtusus= LINDSTR. p. 53. Fig. 45. Horizontal section of cephalic eye near the inferior margin 30/1. » 46. Vertical section, the interspaces being in this wider than in the preceding 60/1. From Gotland. =Dalmanites vulgaris= SALTER P. 54. Fig. 47. Part of the cephalic eye near the inferior margin 20/1. » 48. Horizontal section near the surface at the inferior margin 30/1. » 49. A tangential section, so that the inferior part is below the lenses where the peculiar radiating structure is seen in horizontal section 30/1. » 50. Vertical section of a small Specimen, fibrous appendices below the lenses 30/1. » 51. Hypostoma 2/1. » 52. The right macula 12/1. English specimens from Dudley, Shropshire. =Dysplanus centrotus= DALMAN p. 55. Fig. 53 & 54. Horizontal and vertical sections of an eye 60/1. » 55. Hypostoma 3/1. » 56. The anterior wing of the hypostoma seen in foreshortening 6/1. Specimen AX from Westanå, Östergötland. =Dysplanus ladogensis= HOLM p. 55. Fig. 57. Hypostoma 3/1. » 58. The same, seen from the side 3/1. Specimen AI from Östergötland. K. Sv. Vet. Akad. Handl., Bd 34, No 8. Lindström: Trilobites. Pl. III. [Illustration] G. Liljevall del. Ljustryck af Chr. Westphal Stockholm. Pl. IV. =Chirurus speciosus= HIS. Fig. 1. The right macula, cast of the interior side 12/1. Specimen from Grumpevik, Vamlingbo, Gotland. =Cybele bellatula= DALM. p. 52. Fig. 2. The hypostoma 3/1. Vestanå, Östergötland. =Dalmanites sclerops= DALMAN p. 54. Fig. 3. The hypostoma 2/1. =Encrinurus punctatus= WAHLENB. p. 56. Fig. 4. Horizontal Section of an eye 69/1. Diameter of the prisms 0,04 mill., their length 0,07 millim. » 5. The hypostoma 3/1. » 6. The left macula. Reflected light 12/1. » 7. Part of the left macula in transmitted light 20/1. The black streaks are sectioned pores. Spec. BH. » 8. Vertical section of the right macula, a sagittal section 20/1. BH. » 9. A similar one _a_ along the shorter diameter 20/1. Specimens 5, 6 from Vikers Boge, 4, 9 Medebys, Hall, 7, 8 Svarfvarehuk. All from Gotland. =Encrinurus lævis= ANG. p. 56.