1892.] MICROSCOPICAL JOURNAL. 279 



Philodina. — I cannot identify this species with any of those 

 described. The Rotifer is shown at Fig. 8. 



List of Figures in the Frontispiece. 



1. Notops minor (side view). 



2. " " (ventral view). 



3. Conochilus unicornis Female. 



4. " " Antennse. 



5. Euchlanis parva. 



6. Conochilus unicornis. Male, 



Callidina magna-calcarata. 



8. Philodina (species?). 



9. Triphylus lacustris. Male. 

 10. Notops clavulatus. Male. 



The Grasshopper, ffidipoda Carolina; an Introductory 

 Study in Zoology. 



By H. L. OSBORN, 



ST. PAUL, MINNESOTA. 



The great abundance of grasshoppers, their size and their af- 

 finities to the other insects render them an especially suitable and 

 convenient subject for introducing students to zoological methods 

 of thinking and working. It is possible in the autumn for each 

 student to obtain abundance of material for the zoological study 

 of the insects, and this he should be compelled to do, preserving 

 the specimens in alcohol, to be carefully examined on the lines in- 

 dicated in the present chapter. Specimens may be killed by 

 atmosphere of chloroform and then preserved in alcohol, or they 

 may be dried after chloroforming and mounted on pins as described 

 in Packard's Entomology for Beginners. Dried specimens should 

 be dampened with tepid water or water vapor prior to study. Of 

 course the external parts onh' can be studied in this way, the in- 

 ternal anatomy being destroyed by drying. 



I. External Anatomy. 



The grasshopper presents a body^ to which are attached mov- 

 able organs, called appendages. The body is divided into three 

 regions, which are called head., thorax., and abdomen. The head 

 (Fig. 2) in front bears the mouth, with its appendages and the 

 organs of special sense. The latter are (i) the two antennce., a 

 single pair presenting a number of joints united to the head by a 

 single larger joint ; (3) the compound eyes., globular dark bodies, 

 whose surfaces are minutely subdivided \\\\.o facets., which can be 

 seen with the hand lens ; (3) the three si?}tple eyes., one above each 

 antenna and in front of the compound eyes and one in the front of 

 the head, between the two antennte. The mouth, on the underside 

 of the head, presents four movable sets of parts (Fig. 8) : (i) an 

 upper lip or labrutn ; (2) a lower lip or labiuin ; the labium further 

 presents a median bilobed portion and a pair of palpi., each 3- 

 jointed ; (3) the jyiaxilla: on either side, just in front of the labium, 

 each consisting of an inner portion of several pieces and a 5-jointed 

 onter palpus ; (4) the mandibles, a pair of heavy toothed pieces not 



