902 THE AMERICAN NATURALIST. [VoL. XXXIII. 
on the dipteran side, is a true fly of the family Phoridæ, without any 
siphonapteran affinities. 
The Sting of the Hymenoptera. — Zander has studied the struc- 
ture of the sting in sixty-two hymenopterous insects and, among other 
conclusions (Zeit. wiss. Zool., BA. LXVI, p. 289), comes to the support 
of the views of Heider, Heymons, and Kulagin, that the elements of 
the sting (że. the gonapophyses) are not homologous with the other 
appendages. This conclusion is based on the fact not only that 
these structures arise much later than the abdominal legs, but that 
they arise in a position nearer the middle line than do the transient 
abdominal limbs. 
Nematodes. — Dr. O. von Linstow + has just published the results 
of his studies on the parasitic nematodes of the Berlin Zoological 
Collection. The paper is altogether the most extensive contribution 
to this much neglected and little known group that has appeared in 
recent years. It includes descriptions of forty-nine species, of which 
thirty-eight are new to science. Among them the genus Ascaris was 
represented by twelve species, and Filaria by nine, while the other 
species were distributed through numerous genera, two of which, 
however, were entirely new. These forms were collected from every 
continent except North America and were taken from hosts in every 
group of vertebrates. 
Among items of general interest was noted the abundant occur- 
rence in fish of ascarid larva, often of considerable size, whereas 
Ascaris lumbricoides, the human round worm, of which the life history 
is known, undergoes direct development, z.c., has no intermediate host. 
A striking form is the new genus Pterocephalus from the intestine 
of the zebra in east Africa. The head of the adult’ parasite bears 
six conical spines, six hooks, and six deeply serrated leaf-like append- 
ages which are attached only at their constricted bases. While the 
hooks and spines are directed anteriad, these appendages lie prone 
and reversed; when, however, the mouth opening is drawn in and 
the spines and hooks inverted and concealed, the appendages are ° 
turned anteriad and project from the anterior margin of the head 
curiously like wings, hence the generic name. These structures are 
wanting or only faintly indicated in the immature forms. 
Spiroptera (an Filaria) bicolor, pati: reported el von Linstow 
1 Linstow, O. von. Nematoden aus der Berliner Z 1 Mitth 
a. d. Zool. Sammi. d. Mus. f. Naturk. Berlin, Ba. i, Hft. 2 RH 28 pp., 6 pis. 
