CHAPTER IV. 



ANATOMY OF THE LARVA OF THE GIANT CRANE-FLY 

 (HOLORUSIA RUBIGINOSA). 



As the larvae of Corydalis are not to be found on the 

 Pacific Coast (and in some other parts of the United States) 

 an account of the anatomy of the larva of a crane-fly (Tipu- 

 lidae) is presented for the use of students who may not be 

 able to work with Corydalis. The largest Tipulid is the 

 Giant Crane-fly, Holorusia rubiginosa^ found commonly on 

 the Pacific Coast. The larvae of this Tipulid attain a length 

 of two to two and one-half inches, and by the absence of fat 

 in the body-cavity, and the ease with which they may be 

 perfectly preserved and readily dissected offer especially 

 available subjects for the study of the internal insect anat- 

 omy. As Holorusia does not occur elsewhere in the United 

 States than on the Pacific Coast (as far as is known) students 

 in other regions (in which Corydalis also does not occur) will 

 have to use the larva of some other Tipulid species. Some 

 rather large Tipulid is common in almost every locality. 

 The account of Holorusia will be found to answer as a guide 

 to the dissection of any other Tipulid larva. 



EXTERNAL ANATOMY. 



Technical note. — Bring a number of the larvae of Holo- 

 rusia (or other large Tipulid species, to be found in wet 

 moss, vegetable slime or about grass roots in pastures, etc.) 

 alive into the laboratory. Note the various motions and the 



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