112 HALF-AN-HOUR AT 



like those on some ticks and arachnida. Two moveable appen- 

 dages, one in front of either antenna, near its base, must be care- 

 fully noted. They are called " trabeculse." I take them to be 

 homologous with the " First pair of Antennge " in Crustacea, 

 andfshown us as large moveable organs in Daphnia pulex, here but 

 rudimentary. 



Gizzard of Flea. — The delicate membranous part, looking 

 like a little bag without strings, is a portion of the crop, where- 

 into the blood is pumped during one of the creatures' thoughtless 

 drunken bouts. Thence the food passes into the bowl-shaped 

 middle portion, the gizzard proper. This is lined with teeth, 

 arranged in quincunx with beautiful regularity ; the bases of these 

 teeth appear like fish-scales in the lower part of the bowl, tending 

 more or less to a hexagonal outline as they approach its margin. 

 The points of the teeth project forwards, the whole forming a 

 powerful mill for grinding blood-corpuscles, some of which may be 

 seen in a triturated state along with h^matin in the instructive 

 specimen now before me. Endeavouring to compute the number 

 of teeth, from three professionally-mounted specimens in my pos- 

 session, there appear to be, as nearly as I can make out, just 500 ! 

 It is probable important differences may present themselves in 

 fleas taken from our beds, or from the cat or dog. The long 

 tapering tube pendant from the gizzard is the first part of the 

 intestine ; the dark patches I take to be biUary glands in a simple 

 form. To complete our knowledge of this object we want a 

 specimen mounted, so that we may look into the gizzard from 

 above, and another laid open lengthwise to show the teeth. 



Hippobosca equina belongs to a small section of the Diptera, 

 whose place in a natural arrangement is at the very end of the 

 true insects, and leading directly to the ticks, amongst the acarine 

 division of the arachnida. The section includes but two families 

 — the Hippoboscidce and the NycteribiidcE. The latter family 

 appears to contain but one British genus with a single 

 species parasitic on bats, an anomalous, wingless, spider- 

 like creature, of which specimens are in the collection of the 

 British Museum. It may be considered certain that special 

 search amongst bats of various kinds from different countries will 

 be repaid by many more forms of these remarkable creatures. To 

 the Hippoboscida^ belong the swallow-fly — Stenepteryx Hirundims 

 (easily recognised by its long, narrow-pointed wings), the Sheep 

 Tick, Mdophagus ovimis, and a few others, which are mostly 

 parasitic on birds. Search should be made for them by our mem- 

 bers whenever opportunity offers. The bare enumeration of the 

 points of structure demanding careful study in this beautiful 

 creature would be like a mere Catalogue raisomie, for nothing in 



