288 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



Holniia [pi. 27, fig. 7] differs from Callavia [pi. 27, fig-, i] in 

 having an expanded frontal glabella lobe ; in its spinose extensions 

 of the pleura : and small occipital spine. From Wanneria [pi. 30, 

 figs. 2 and 6] it varies in not having a great spine on the fifteenth 

 segment, and in having spinose extensions of the pleurae. The latter 

 character is similar to that in the thorax of EUiptocephala [pi. 24,. 

 fig. i] and Mcsonacis [pi- 26, fig. ij. 



Holmia follows Mesoiiacis and CaUaitia in the scheme of classifica- 

 tion of the Mesonacidae because it is considered that the thorax indi- 

 cates a stage of development slightly more advanced than in those 

 genera. The latter still retain the partially developed posterior 

 segments that appear to have disappeared in Holmia, 



Dr. G. F. Matthew [1899, p. 59] in his review of Moberg's paper 

 [1899, pp. 309-348] mentions that there are two types under Holmia 

 as arranged by Moberg [1899, pp. 314 and 318], the first two species 

 mentioned after Holmia kjcrulfi being distinguished from the geno- 

 type by a difl:'erence in the number of the segments in the thorax, 

 and possessing a conical in place of a club-shaped glabella. The 

 species are H. hroggeri Walcott and //. callavei Lapworth. These 

 forms are now included in the genus Callaz'ia. 



HOLMIA KJERULFI Linnarsson 



Plate 27, Fig. 7 



Paradoxides kjcrulft Linnarsson, 1871, Ofversigt af Kongl. Vet. AkacL 

 Forhandlingar, pp. 790-792, pi. 16. figs. 1-3. (Described and discussed.) 



Paradoxides kjeruM (Linnarsson). Kjerulf, 1873, Om grundfjeldets og 

 sparagmitfjeldets niaegtiglied i Norge. 2. Sparagmitfjeldt, p. 83, text 

 figs. 1-5. (No text reference.) 



Olcncllus kjerulfl (Linnarsson), Brogger. 1878, Nyt Mag. for Naturvid... 

 Bd. 24, p. 44. (Mentioned.) 



Paradoxides kjcruHi Ford, 1878, American Journ. Sci., 3d ser., Vol. 15, p. 

 130, footnote. (Discusses generic relations of Paradoxides as repre- 

 sented by P. kjerulfi with Olenellus as represented by O. asaplioides.) 



Paradoxides ? kjenilfi (Linnarsson), Ford, t88t. American Journ. Sci., 3d 

 ser.. Vol. 22. pp. 255-258, text fig. 10, p. 256. (Gives a diagrammatic 

 figure of the cephalon, and discusses the relation of the species to 

 Olenellus asaplioides and of Paradoxides to Olenellus.) 



Olenellus kjerulfi Linnarsson, 1883, Sveriges Geol. Unders., Ser. C, No. 

 54, pp. i'8-20, pi. 3, figs. 12-17. (Describes and illustrates specimens 

 from Andrarum.) 



Paradoxides kjerulfi (Linnarsson), Walcott, 1886, Bull. U. S. Gcol. Sur- 

 vey, No. 30, p. 178, pi. 20, fig. 2. (Compares occular ridge and facial 

 suture back of the eye? with those features in Olenellus gilberfi. 

 Figure 2 is an outline drawing of the figure given by Linarsson [1871,. 

 pi. 16, fig. 2].) 



