304 The American Geologist. May, 1896 
A critical examination of the available data relating to 
these statements seems desirable in view of its importance, 
and from the fact that the most recent researches on the 
structure and affinities of trilobites date from the discovery 
of the antenna' of Triarthrus by Valiant, as published by 
Matthew 8 in 1893. 
The foregoing- observation by Linnaeus has not been over- 
looked, as Tornquist supposes, for nearly a hundred and 
forty years, but was undoubtedly given all the consideration 
it merited. Brongniart, s in 1822, describes an individual of 
the same species (P. spinulosa) in which there was a sugges- 
tion of an antenna produced by an impression of a portion of 
the head of another specimen. He remarks (loc. cit.. p. 33) 
that "cette circonstance me fait soupconner que cet echantillon 
pourrait bien etre celui qui a ete figure par Linne dans les 
Memoires de 1'Academie de Stockholm. On sait qu 'on y a 
dessine des antennes ; il est possible que cette empreinte ait 
etc prise pour cette partie par le peintre." And in the intro- 
ductory portion he says (p. 5), "Entin ni moi, ni aucun des 
observateurs qui ont etudie ees animaux n'y ont jamais rien 
vu qui put etre compare a des antennes on a des pattes." 
The original figure by Linnaeus was also cited by Dalman, 6 
in 1828. who says of it (loc. cit., p. 73), *'Sed capite exserto 
et antennis praedito delineatus!" Wahlenberg and Angelin 
give the same references to the original, and the former in 
describing his species Entomostracites spinulosus, in 1821, in- 
cluded in it the specimen of Entomolithus paradoxus of Lin- 
naeus with the supposed antennae. 
Any one who will take the trouble to examine Linnaeus' 
tigure will concede at once that it is a very crude representa- 
tion of a trilobite, and is an especially poor illustration of 
the species, Parabolina spinulosa. .lust why it was referred 
to this species cannot now be easily ascertained since it lacks 
all the really specific characters attributed to this form by 
Angelin, 1 and later, with greater accuracy, by Brogger. 4 Lin- 
meus 1 figure gives no suggestion of the nodes on the annula- 
tions of the'axis. nor of the characteristic long pygidial and 
pleural spines. The genal spines are also wanting as well as 
the eyes, the^ f ree cheeks, the facial sutures, and the surface 
markings. Even Wahlenberg 10 and Dalman 6 were in doubt as 
