ISTo. 64] DIPTERA OF CONNECTICUT: MORPHOLOGY 59 



ent structures in other insects are applied to the calypteres of the 

 Diptera by some writers (as is the case with the term tegulae, etc.), 

 with the result that a most disconcerting confusion has arisen, and it 

 is highly desirable that an attempt be made to establish a uniform 

 terminology for the structures in question, which will be acceptable 

 alike to the taxonomists and the morphologists. In order to select 

 the most appropriate designations for these structures, it may be of 

 some value to review the terms which have been applied to them. 



On page 584 of the well-known tenth edition of the "Systema 

 Naturae," Linnaeus (1756) lists the distinguishing characters of the 

 Diptera as follows : ''Alae duae. Halteres clavati, solitarii, pone sin- 

 gulam alam, sub squamula propria." Linnaeus thus designates the 

 (lower) calypter which covers the halter, as a squamula; and Curtis 

 and a number of other dipterists likewise apply the designation squam- 

 ula to the calypteres. Lowne (1890), however, restricts the designa- 

 tion squamula to the upper calypter, del of Fig. 7, 1, and designates 

 the lower one, 5c?, as the squama. Osten-Sacken (1896, p. 286) states 

 that "squama or squamula was the term almost universally used (for 



the calypteres) Fabricius, Fallen, Meigen, Zetterstedt, Erichson 



(die Henopier), Schiner, all have squama. lUiger, Terminologie 

 (1800, No. 1818) has squama halterum." On page 288, Osten-Sacken 

 (1896) suggests that the calypteres be called squamae when taken to- 

 gether, but that when they are considered separately, the lower one 

 should be called the squama, while the upper one should be called the 

 anti-squama. 



Audouin, who is responsible for most of the terms now used for 

 the parts of the thorax in insects, applied the term squamula to the 

 true tegula in Hymenoptera (see footnote to page 41, Vol. 25, of the 

 Ann. Sci. Nat., Ser. I, 1832) , as also does MacLeay, who attributes this 

 usage to Latreille. The term squama, however, is used for the lens- 

 shaped basal segment of the abdomen in ants, as well as for the scle- 

 rite which bears the palpus in the maxilla and labium of Odonata, and 

 for one of the sclerites of the genitalia, etc., so that the terms squamula 

 and squama cannot be restricted to the calypteres of the Diptera with- 

 out creating confusion ; and furthermore, the term squama is too much 

 of a general descriptive designation for any scale-like structure of the 

 body, to be restricted to a single structure, as must be done in em- 

 ploying an exact morphological terminology for definite parts of the 

 body. 



Kirby and Spence (1826, Vol. 3, p. 625) called the calypteres 

 "alulae or winglets", and this usage was adopted by Westwood, Walk- 

 er, Haliday, and other British dipterists, but many other dipterists 

 have followed Loew (1862, page xxi, and Fig. 1, page xxiv, of the 

 chapter on "terminology") in restricting the term alula to the axillary 

 lobe of the wing, alo of Fig. 7, 1 ; and this usage has become quite gen- 

 eral among modern dipterists. 



Loew (1862, page xiv of the "terminology") applies the term 

 tegulae to the calypteres, and Osten-Sacken at first adopted this us- 

 age, applying the term tegula to the proximal or lower calypter, and 

 calling the distal or upper calypter the antitegula. Later, however. 



