THE GENUS ENCRINURUS 
Its History, Its Species, Its Proper Division in the Family of Trilobites 
A. W. VOGDES 
OF SAN DIEGO, CALIFORNIA 
: Specimens of this ‘Trilobite were known almost 200 years ago; the 
first to Herrmann, who, in his Maslographia, plate 9, fig. 50, represents 
a tail of this genus, with six nodes on the axis and nine pleurae; he 
names it Pectunculttes marmoreus trilobus imbricatus. ‘This book was pub- 
lished in the year 1711. For copy of original see plate 3, fig. ro. 
Some fifty years afterwards Linné, in Act. Reg. Acad. Sci. Holmiens, 
P. 22, plate 1, fig. 3, gave a figure of a specimen from Gotland, under the 
Seneral name for all ‘T'rilobites, that of Hx/omolithus paradoxus, For copy 
of original see plate 3, tip. it. 
The author illustrates a tail with 9 pleurae and 20 axial joints; they 
ue notched at the sides: this species served for the type of Wahlenberg’s 
Entomostracites punctatus. 
Other authors, such as Lehman, Novi Comm. Acad. Sci. Imp., vol. 
TO, plate 3, fig. ro, and Wilckens, Stralsundishes Mag., vol. 4, 1769, p. 267, 
Plate 3, fig. 12, gave illustration of the pygidium, but without generic or 
Specific description. 
Wilckens has the credit of placing the fossil under the Crustacea. He 
Copies Herrmann’s figure and names the fossil “ Entomolithum Branchio- 
podis ca ncriformis marint,”’ 
: Under the general term of ‘Trilobus, Brunnich Nye Samling, af det 
Kong. Danskse Vidensk. Skrifker, vol. 1, 1781, p. 394, gave a specific 
hame to the fossil now known as Encrinurus punctatus. 
The author remarks: ‘‘ Of the two very imperfect fossils I found in 
@ soft yellowish limestone from Bohemia, I find across the fossil body 
impressed spotted joints, which are sufficient to distinguish it from other 
Species. ‘The size of it seems to vary greatly, as my limestone contains 
One small and one very large tail; each has 18 joints.’’ 
Wahlenberg, in his Petrificata telluris Svecanae Upsaliae, 1818, p. 
a, plate 2, fig, 1*, not fig. 1 (Calymmene Blumenbach?), under the gen- 
Cral name of Entomostracites punctatus, figures a specimen from Gotland. 
