The Crane-Flies of New York — Part I 855 



femora, the mesotibia, and so on. In addition to the thoracic segments 

 there are some tiny sclerites between the head and the prothorax, called 

 the cervical sclerites and comprising the neck, or microthorax. 



The prothorax. — In the Tipulidae the pronotum, or dorsal sclerite 

 of the prothorax, consists of two regions which are usually interpreted 

 as being homologous to the scutum and the scutellum of the mesonotum, 

 described and illustrated below. In this paper these regions are called 

 the pronotal scutum and the pronotal scutellum. The propleurites are 

 made up of the usvial pleural plates, which are discussed in the description 

 of the mesothorax ; these are termed the proepisternum and the proepimeron. 

 The sternal region of the prothorax is the presternum. In the family 

 Tipulidae the sclerites of the pronotum are usually small and insignificant, 

 being encroached upon by the sclerites of the mesothorax. In some 

 exotic genera, such as the tropicopolitan genus Styringomyia, the pro- 

 thorax is large and of a generalized structure. In entomological 

 literature the pronotum is usually spoken of as the ''neck" or the 

 "collare." 



The mesothorax. — The mesothorax is the principal region of the thorax 

 in the Tipulidae. The mesonotum, or upper part, is divided into two 

 sclerites, which are again divided so as to appear as four — the prescutum, 

 the scutum, the scutellum, and the postnotum. 



The prescutum is the anterior, or first, subdivision. In crane-flies 

 it is the largest single region of the thorax, lying behind the pronotum 

 and before the transverse, or V-shaped, suture. It may be very flat and 

 depressed, as in the South African genus Platylimnobia, or very high 

 and gibbous, as in Dicranomyia glohithorax, D. gibbera, and other species; 

 or it may jut far cephalad over the pronotum, as in Conosia and in many 

 species of Trentepohlia. In the subgenus Conorhipidia of the genus Rhipi- 

 dia, which includes two species from tropical America, the prescutum is 

 elevated into a high conical point, which is very remarkable but is sug- 

 gested in other species of the same genus, as, for instance, Rhipidia domestica. 

 The prescutum is usually striped in various ways, a common pattern 

 being three stripes, one in the middle and two shorter ones on the sides. 

 The spaces between these stripes often bear setigerous punctures, with 

 setae of various forms and sizes. In many genera the prescutum bears 

 two shiny dots, called tuberculate pits (fig. 126, b). In certain groups, 



