442 ANNUAL ItECORD OF SCIENCE AND INDUSTRY. 



trum overhanging the head, stalked eyes, and, besides two 

 pair of antennae and mouth-parts, eight pair of leaf- like, 

 short respiratory feet, which are succeeded by swimming- 

 feet. There is no metamorphosis, development being direct. 

 Of the fossil forms, Ilymenocarls was regarded by Salter as 

 " the more generalized type." The genera Peltocaris and 

 Discinocaris characterize the Lower Silurian period, Ceratio- 

 caris the Upper; Dictyocaris the Upper Silurian and lowest 

 Devonian strata, and Dithyrocaris and Argus the Carbonif- 

 erous period. Our northeastern species is Kebalia bipes 

 (Fabricius), which occurs from Maine to Greenland. The 

 Nebaliads were the forerunners of the Decapoda, and form, 

 according to A. S. Packard, Jun., the types of a distinct order 

 of Crustacea, for which he proposes the name Phyllocarida. 



Insects. 



In an interesting article on insect sounds, by Dr. II. E. 

 Tripp, published in the Proceedings of the Bristol Natural- 

 ists' Society, the author takes the ground that the sounds 

 made by bees, flies, gnats, and the Cicada are vocal sounds, 

 made by the air rushing from the spiracles or breathing- 

 holes in the thorax, which constitute vocal organs, the tone 

 produced being a reed-sound, the insect having, as it were, 

 one or two pairs of mouths. Distinguishing insect sounds 

 by the mode in which they are instrumentally produced, w r e 

 may classify them as: 1. Stridulant tones, as of a rasp or file, 

 the stridulation being produced by the rapid click of toothed 

 processes. 2. Wing tones, as simple vibration of air. 3. 

 Voice, as a reed-tone, essentially consisting of vibration of 

 membranes. 4. Noises, or interrupted concussion-sounds, as 

 when parts of the body are struck against each other or 

 against foreign bodies; or, as in some rare cases, air-volumes 

 expelled from the interior of the insect; or, again, as in the 

 movements of the wings in certain Acrydii (grasshoppers). 



The sounds made by most insects are undoubtedly sexual 

 calls. Thus Hartman writes that in June, standing: in a 

 dense chestnut forest, he saw the voiceless females gather 

 from all directions, while the males shrilled their love-calls. 

 Landois, in an entertaining work on Animal Sounds, states 

 that in many cases the object of insect-sound is the preser- 

 vation of the individual, as many insects make no sound ex- 



