214 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



resent the modified limbs of the eleventh segment which enters into 

 the composition of the proctiger. The cerci tend to unite mesally 

 in certain of the higher Diptera, but frequently remain distinct in 

 the Cyclorrhapha, and are usually better developed in the males than 

 in the females of these Diptera," being extremely long and well de- 

 veloped in the males of such Cyclorrhapha as the one shown in Fig. 



7, K. 



The cerci, ee, may serve as copulatory prongs m male Sarcophagi- 

 dae (Fig. 14. B), in which group they are referred to as the "forceps" 

 by Parker (1914), Aldricli (1916), and other students of these Dip- 

 tera. Metcalf (1921) lists the designation lamellae of Lundbeck, 

 forcipes superiores of Wesche, 1906, (substituted by him for Lowne's 

 designation valvulae internae), and acrocerci of Berlese (1909), as 

 some of the terms applied to the cerci by other dipterists, and New- 

 stead's designation superior claspers for the parts in GJossina was 

 evidently suggested by Wesche's designation "forcipes superiores", 

 cited in Metcalf 's list. Hendel (1928) adds the designations valvulae 

 mediales, mesolobes, etc., to the list of terms applied to the cerci, and 

 Patton (1932) remarks that a "host of names" have been applied to 

 these structures, adding the designations lamina genitale, mesocerci, 

 etc., to those mentioned above. 



The terminology and interpretations adopted in the foregoing- 

 discussion are those which have seemed to be most nearly in accord 

 with general morphological usage, and it is to be hoped that this 

 discussion may be of some aid in attempting to establish a uniform 

 terminology for the external structures of the Diptera in general, 

 which must be undertaken unless the present confusion in the termin- 

 ology applied to the parts of the Diptera is to continue indefinitelj'. 

 The terminologies and interpretations proposed in all of the more 

 important papers dealing with the subject have also been discussed at 

 length, in order to make it easier to refer to the original sources, in 

 attempting to decide which interpretations are more nearly cor- 

 rect, or are more in harmony with general morphological usage. 

 The appended bibliography has also been made as complete as pos- 

 sible, to the end of the year 1935 (at which time the original manu- 

 script for this chapter was first completed) to aid in referring to the 

 publications which contain figures and descriptions of the external 

 structures of the Diptera. 



It has naturally been impossible to include descriptions of all 

 of the structural modifications occurring in such a large group as the 

 Diptera, in the foregoing discussion, but an effort has been made to 

 include descriptions of the principal basic or fundamental types in 

 this discussion, so that the parts of the commoner forms, at least, may 

 be readily referred to some one of these types for comparison, to 

 determine the homologies of the structures occurring in them. In 

 addition, descriptions of the most striking modificational extremes 

 occurring in the Diptera have also been included, in order to indicate 

 the range of structural variations occurring in the Diptera in gen- 



