62 
Brongniart, who was the first author classifying the T'rilobites, in 
his excellent work Hist. Nat. Crust. Foss., 1821, places this fossil under 
his genus Calymmene, naming it Calymmene variolaris, p. 14, plate 1, 
figs. 3 a-b. 
Burmeister Org Trill., p. 114, and other authors, refer Brongniart’s 
plate 1, figure 3a, to Excrinurus punctatus, and his fig. 3b to Z. vario- 
laris. ‘The first is an extended specimen, with the genal angles pro- 
longed into spines; the second a rolled up specimen, in which the genal 
angles are not extended into spines. 
The characteristics of the pygidia are amply sufficient to separate the 
two common species. “4. variolaris has 9 axial joints, interrupted in the 
middle by one or two isolated nodes on each joint, with 7 pleurae, and the 
axis is not extended into a long caudal spine, as in 4°, punctatus. 
The Rev. Dr. Buckland, Geol. & Mineral Bridgw. Treat., vol. 2, 
1837, copies Brongniart’s figure, plate 1, fig. 3a, on plate 64, fig. 6, under 
the new name Asaphus tuberoulatus. 
Dalman Paleeden, 1826, p. 234, plate 2, fig. 2a-b, gives figures of 
Gotland specimens No. 6, Calymmene punctata, and corrects the error of 
Wahlenberg’s reference to plate 1, fig. 1* (the head of Calymmene Bilu- 
menbachi, to this species). 
Murchison, Syst. Silurian., plate 23, fig. 8, illustrates 4. punctatus, 
and on plate 14, fig. 1, an entire specimen of /. variolarts erroneously 
figured with 13 thoracic segments. 
Emmrich De, Tril. Dis., 1839, p. 20, describes under the genus 
Phacops vartolaris a species with the posterior angles of the head produced 
into short horns, a common characteristic of the other species, Axcrtnurus 
punctatus. 
As late as the year 1840, the then known two species of this genus 
were classified under the genera Asaphus, Calymmene and Phacops. 
Kichwald at this date proposed that of Cryptonymus for the generic 
name (Sil. Syst. Hsthlands, 1840, p. 71). The author placed such specie as 
Calymmene punctata and C, variolaris, including in the new genus C. 
Woerthi C. parallelus, now classed under the genus Cybele. The author, 
in substituting his abandoned name of Cryptonymus (proposed Obser. 
Geog. Zool! per Ingram. Marique Baltice, 1825, p. 44, there used for 
eight species, now classed under the genera Asaphus and Illaenus), simply 
pointed out his generic types without giving a generic description. 
This name should stand under the strict rule of priority, for at least 
such species as /:ncrinurus punctatus or /¢. variolaris,; and it was so used 
by Angelin in his Palaeont. Scand., in which he gave a description of 
the genus, 
Hichwald, Bull. Soc. Imp. Sci. Moscow, 1855, claims priority and 
gives a history of the generic names. 
