Miscellaneous. 317 
marked with exceedingly regular, delicate, longitudinal, parallel lines 
about 1-9375th in. apart, apparently muscular in character. 
Length from 1-160th to 1-30th in., by 1-830th to 1-111th in. in 
breadth. 
Hab. Found in numbers of from half a dozen to over a hundred, 
in the ventriculus of Judus marginatus. 
Gregarina is probably the larva condition of some more perfect 
animal, but in the 116 individuals of Ju/us which I have examined, 
I have not been able to detect any form which could be derivable from 
it. Creplin doubts its animality*. When I first discovered this 
body, thinking it to be a larva, I did not examine it carefully, and it 
was not until some time afterward, when, being desirous of ascertain- 
ing its true nature, upon examining some fresh specimens beneath 
the microscope, I detected movements of an animal character, and this 
led me to seek for muscular structure, which resulted in the discovery 
of the longitudinal lines of the inferior cell. These escaped the ob- 
servation of Siebold, for he says, ‘‘ Nach meine Beobachtungen bestehen 
die Gregarinen aus einer harten glatten den Eihillen der Insekten-Eier 
ahniichen Haut+.” The movements of the animal are exceedingly 
sluggish, and consist of a very slow bending in any direction of any 
part of the inferior cell, most usually above the middle, rarely at the 
inferior extremity, but most frequently near the superior cell which 
is entirely passive. The superior cell is also frequently drawn or con- 
tracted within the inferior, and again protruded by the contraction of 
the latter, and the propulsion of the granular contents against it. 
The inferior cell is also frequently, more especially in younger indi- 
viduals, intus-suscepted within itself through a partial contraction, and 
again relieved by a general contraction of the cell-wall. 
In the state in which Gregarina is found, it would probably hold 
a rank between the Trematoda and Trichina, the lowest of the Ne- 
matoidea.—Proceedings of the Academy of Natural Sciences of Phi: 
ladelphia, vol. iv. p. 229. 
On the mouthless Acari which have been formed into the genus 
; Hypopus. By F. Dusaroin. 
Degeer, Hermann and Geoffroy found upon various insects some 
very small parasitical mites, to which they gave the name of Acarus 
muscarum and Acarus spinitarsus ; they were not, however, able to 
study them on account of their extreme minuteness. Dugts, who 
examined a single one only, constituted the genus Hypopus of it, 
characterized by a sucker, provided with two rigid bristles, but re- 
gretting at the same time that he had not sufficiently studied it. 
Since that period, M. Léon Dufour has made known two other 
species, and M. Gervais has described 2 fifth species; but he has 
mistaken the projecting lines resulting from the contiguity of the 
hips for a nervous system. M. Koch in Germany has also described 
two other species of them, but without making any attempt at inves- 
tigating their organization. M. Dujardin, who in 1842 described, 
* Nachtrage zu Gurlt’s Verzeichniss der Thiere bei welchen Entozoen 
gefunden worden sind. Wiegmann’s Archiv, 1846, 1 Band, S. 157. 
t+ Wiegmann’s Archiv, 1838, 2 Band, S. 308. 
