K0NGL. NV. VET. AKADEMIENS HANDLINGAR. HAND 34. N:o 8. 57 



Holmia Walcott. 



Holmia Lundgreni Moberg, Sveriges äldsta trilobiter, Tall. II. fig. lo, II, 12. 

 The maculae are much promineni and tubercula.r, elongate narrow, oblique l»ul not men- 

 tioned in the description. HypostoniM p robably belonging to the terrace-line group. As 

 well seen in original specimens and in the figures in Dr. Holm's paper on Olenellus 

 (Holmia) Kjerulfi there are also in this species two distinct maculae near the posterior 

 margin of the hypostoma, above the marginal groové. 



Homalonotus K 



ONIG. 



Maculae liave been previously observed in the following species. 



Horn. delphinocephalus Gkeen, Hall Pal. N. York vol. II pl. 68 fig. 11, incomplete 

 figure with twö well marked tubercular maculae. No description. 



Horn. Knighti Koenig. Salter II, pl. 12 fig-. 10. Maculae well expressed as oblique 

 tubercles. On page 120 it is said »with a pair of lateral tubercles well developed (as in 

 Asaphus . . .)». 



This species is identical with Angelin's Hornalon. rhinotropis, Pal. Se, pl. XX fig. 

 1 e and his figure has two hollow maculae seen from the inside of the hypostoma. 



Homalonotus Kuighti König (== Homal. rhinotropis Angelin). 



Pl. IV tigs. 20, 21. 



The maculae lie as oblong, smooth tubercles surrounded by the irregularly grown 

 granules of the surface, just below the central globosity of the hypostoma. In a prepara- 

 tion from the interiör surface of the macula, as seen in transmitted light, fig. 21, this is 

 white with only a few grey spöts and on the superior börder black streaks, lying ob- 

 liquely. The substance of the shell around the macula is perforated by the minutest 

 pores amongst which a few larger are intermingled. The granules are also perforated 

 as those in Calymmene and the tubes continue through the shell, visible by their black 

 colour. 



Hysterolenus Moberg. 



Hyst. Törnquisti Mhg, En trilobit från Dictyograptusskiffern p. 320. In the de- 

 scriptive letterpress, there is said, that in the exteriör (lateral) parts of the anterior 

 groove of the hypostoma a distinct tuberele is to be seen on each side. But none of 

 the figures given, Pl. 17 tigs. 6, 7, shows them or at least verv indistinctly. 



Illaenus Dal 



MAN. 



It is remarkable, considering the great number of species in this almost exclusively 

 Lower Silurian species, that there is none but a single species in which the maculae 



