400 Miscellaneous. 
first and seventh arches; on the others the fringes are developed 
from the outer and convex portion of the arch, and are not at first 
prolongations of the internal gills. 
(6.) The nostrils, as in all Vertebrates, consist at first of pits or 
indentations in the integuments; secondly, a lobe is developed on 
the inner border of each ; and, finally, the two lobes become con- 
nected, and thus form the homologue of the fronto-nasal protu- 
berance. The transitional stages of these correspond with the — 
conditions of them in other species of Selachians. 
(7.) The nasal grooves are compared with the nasal passages of 
air-breathing ofall and the cartilages on either side of these to 
the maxillary and intermaxillary bones. 
8.) The foremost part of the head is formed by the extension of 
the facial disk forward. While this extension is goimg on, the cere- 
bral lobes change their position from beneath the optic lobes to one 
in front of them. 
(9.) Two anal fins, one quite large and the other very small, are 
developed, but both are afterwards wholly absorbed. 
(10.) The dorsals change, position from the middle to the end of 
the tail. At the time of hatching, however, there is still a slender 
terminal portion of the tail, which is afterwards either absorbed or 
covered up by the enlarged dorsals, as they extend backward.— 
Memoirs of the American Academy, vol. ix. pp. 31-44. 
On Dimorphism in the Hymenopterous Genus Cynips. 
By Bensamin D. Watsu, M.A. 
The Cynips studied by Mr. Walsh make galls on a species of oak, 
the Quercus tinctoria. Part of these galls produce males and fe- 
males of the Cynips spongifica in June. Another portion of them, 
of wholly similar general character, remain green till autumn, ane 
produce in G@rraber and November, and also in the following spring, 
another form of Cynips—the Cynips aciculata, hitherto regarded as 
a distinct species, all the individuals of which are females. Mr. 
Walsh appears to prove that the latter, although widely different in 
many characters, is only another form of the C. spongifica, and 
thence that this species is dimorphous. The individuals produced 
in June live but six or eight days; what place in nature, then, the 
author asks, is filled by the C. acteulata? In reply, he suggests, from 
the analogy of Apis, Bombus, &c., that “the female aciculata gene- 
rates galls, which produce by parthenogenesis male spongifica, and 
that the females and males of the latter, coupling in June, oviposit 
in the same month, in the young buds of the oak, eggs that remain 
dormant till the following spring, some of which then produce female 
spongifica in June and some female aciculata in the autumn or early 
in the following spring, and these last, in their turn, generate male 
spongifica to appear in the following June.’ He continues, “ It may 
also be the case that some few male spongifica are generated by fe- 
male spongifica.” The author next sustains this opinion by men- 
tioning some of the anaiogies that have been observed in other 
Hymenopterous insects. — Proceedings of the Entomological Society 
of Philadelphia, March 1864, pp. 443-500. 
