;',:! I The American Geologist. November, 1893 
American species of Spothiocaris, S. Emer8oni,h.as been locally found 
by hundreds, but never yet, so far as known, in any intimate or sug- 
gestive association with goniatites, and the only evidence which Ameri- 
can specimens have afforded of the possibility of the cephalopodous 
nature of these fossils is that furnished by one figured upon plate 
.'{•") (fig. 22) of the Paleontology of New York, vol. vii, a very small Dip- 
terocaris-like shield resting upon the chamber wall of a goniatite, the 
diameter of whose aperture is many times the length of the debatable 
body. 
Sveriges Kambrisk-siluriska Hyolithidce och Conulariidce,hy Gerard 
Holm. With an English summary. (Sveriges geologiska Undereok- 
ning, Ser. C, No. 112) pp. i-ix, 1-158, pis. 1-6, 4to, 1893. 
Nothing so elaborate upon these families commonly referred to the 
Pteropoda (a view to which the author, in common with Neumayr, de- 
murs), more especially upon that of the Hyolith idee, has before appeared, 
and the work is in every respect an admirable contribution to the syste- 
matics and structure of these fossils, fully illustrated with finely drawn 
and beautifully printed plates. 
The genus Hyolithus (this form of the word is preferred to Hyolitlies) 
is given a comprehensive meaning and is made to embrace a number of 
generic designations which have quite generally been accorded an inde- 
pendent value, such as Pharetrella Hall, Camarotheca and Diplotheca 
Matthew, Orthotheca, < 'eratotheca and Bactrotheca Novak.* 
As far as the 44 Swedish species (37 new) are concerned, the genus is 
divided into two subgenera, Orthotheca and Hyolithus s. str., the dis- 
tinction being based wholly upon the form of the aperture; in Ortho- 
theca it is in one sloping plane, while that of Hyolithus s. str., is in two 
planes which form a re-entrant angle at their junction. Conularia 
/Family Conulariidce) is treated without subgeneric division under 1G 
species, and appended is a description of the new family Torellellidce, 
erected to embrace the new genus Tore! lei la, with two species. The 
latter are small tubular fossils, very slowly tapering, nearly circular in 
cross-section and with a straight aperture; resembling shells of Salter- 
ella and Coleolus. One of the species (T. laevigata) is team the lower 
Cambrian, the other (T. taenia) from the lower Silurian. These three 
families and genera are treated as having no close relationship either 
among themselves or to the pteropods. Instructive chapters on classi- 
fication, distribution and preservation accompany these descriptions. 
Larval Forms of Trilobites from the Lower Helderberg group ; byC. 
E. Beecher. (American Journal of Science, Aug. 1893, pp. 142-147 
pi. 2.) 
This number of the American Journal contains two highly important 
papers on the trilobites, one a remarkable contribution on their anat- 
*As incidental reference is made to the genus Clathroco'lia Hall, a name introduced 
for a supposed pteropodous shell from the Hamilton group of New York, it may be 
well to observe that this name is to be expunged from scientific nomenclature, as the 
fossils upon which it was based prove to be but the thickened posterior wing of the 
lamellibranch Actinopteria decussata. 
