ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
471 
not of four, but of six cells; nuclei, which are generally persistent 
throughout life, are only found on these cells in quite young examples 
of S. coleoptrata. The crystalline body, as the structure may be called, 
does not, like the cone of true facetted eyes, lie in front of the nervous 
portion of the eye, but is largely enveloped by it. The retinal portion 
consists of two layers of cells, in the upper of which there are twelve, 
and in the lower four retinular cells, whereas the ordinary number is 
seven. 
A new Stage in the Development of Male Iulidae.* * * § — Herr C. 
Verhoeff found in an autumn collection of Hemipodoiulus Karachi that all 
the adult males had the first pair of legs hook-shaped, and were thus 
different from those collected in May and June, whose first limbs were 
leg-like. The two sets agree in form, sculpturing, colour, size, and in 
the characters of the anal segment, foramina, ocelli, antennae, and head ; 
they differ as to “ cheeks,” first pair of legs, and copulatory organs, the 
autumn males representing an adult stage, the spring males an inter- 
mediate stage (status medius or Schaltstadium). The embryological and 
taxonomic importance of this discovery is emphasized. 
5. Arachnida. 
Extreme Case of Parasitism-! — Dr. R. Hessler relates a case of a 
partly paralysed man whose body was covered with thick scales, which 
literally covered him like a fish. These were found to be due to itch- 
mites, of which it is calculated that there were on his body two millions, 
while of egg-cases and eggs there were seven millions. As in an ordi- 
nary case of itch the number of mites does not exceed one hundred, it is 
clear that this may well be called an “ extreme case.” 
Circulatory Apparatus of Mygale csementaria.!— M. M. Causard 
states that the heart of this tetrapneumonous Spider resembles in many 
points that of other Araneidas. There are four pairs of ostia, whereas 
dipneumonous Araneids have three pairs, or, in rare cases, less. The 
heart of Mygale Blondii is stated by Blanchard to be divided into 
chambers ; but this is not the case in M. csementaria , where there is but 
a single chamber with four enlargements. There are only two pairs 
of pulmonary veins ; the blood is brought back to the heart by a pair of 
large lateral arteries, and two which are much smaller. Between the 
origin of these last there is a large trunk which takes a vertical course, 
and soon gives off backwards a branch which the author considers as 
corresponding to the caudal artery of other Araneids ; later on it divides 
into two branches which branch right and left of the digestive tube, and 
ramify in the posterior region of the abdomen. 
e. Crustacea. 
Cement-glands of Lobster. § — Mr. F. H. Herrick has a note on the 
cement-glands and origin of egg-membranes in the Lobster (Homarus 
americanus ). The gland appears to be limited to the five anterior pairs 
* Zool. Anzeig., xvi. (1893) pp. 20-6. 
f Amer. Natural., xxvii. (1893) pp. 316-52. 
t Comptes Rendus, cxvi. (1893) pp. 828-30. 
§ John Hopkins Univ. Circ., xii. (1893) p. 103. 
