884 The Poison-Apparatus of the Mosquito. 
they had coiled young stages similar to those of the normal forms 
from which they must have originated. 
The correlations of Nostology can only be artificially separated 
from those of Clinology, but there existed one class of forms which 
can be compared only with the nostologic stage. These are the 
degenerate straight Baculites-like shells, which belong to several 
distinct genetic series and should often be widely separated on that 
account. Their resemblances are undoubtedly close, but they are 
due to degeneration and, therefore, simply homoplastic. Naturalists 
sooner or later will begin to recognize that degeneration may pro- 
duce close representation in forms having distinct origins. The 
Baculities is a smooth, straight, cylindrical though slightly com- 
pressed shell, which has socompletely reverted that it resembles an 
Orthoceras, though it isan unquestionable Ammonoid of the Jura 
and Cretaceous. 
THE POISON-APPARATUS OF THE MOSQUITO. 
BY PROFESSOR G. MACLOSKIE, 
T oral armature or proboscis of the mosquito ( Culex) is 
described and figured in Dimmock’s Mouth-parts of Some 
Diptera, and consists of a labrum, two mandibles, two maxille, 
surrounding a hypopharynx, and all these enclosed in a loose 
scale-covered sheath, which is the labium. They are nearly three 
millimetres long, about four times as long as the head; and all 
except the sheath are smooth, chitinous stylets. The maxille 
bear maxillary palps, scaly, four-jointed, about as long as the 
head in Culex, and three times as long in the allied genus Ano- 
pheles. I have only to add to Dimmock’s description that besides 
the somewhat coarse serration of the maxilla (about fifteen teeth 
near the top of each), Minot S. Morgan, of Princeton, has shown 
very fine serrations on the upper part of the mandibles (about 
forty-two minute teeth on each). : 
The hypopharynx is in the axis of all these mouth parts, bemg 
inserted by a basal enlargement close behind the oral aperture, and 
