252 PROCEEDINGS OP THE ACADEMY OP 



The name Protoplasa alludes to the close relation of this genus to a 

 fossil form. 



P. Fitchii. Cinerascens, pedibus pallidis, alae maculis ocellaribus brun- 

 neis, in fascias confluentibus, ornate ; long. lin. 3-3^. 



Head cinereous, proboscis and palpi fuscous, antennae infuscated. Thorax 

 cinereous, with three faint brown lines on the praescutum ; scutellum pale, 

 infuscated in the middle ; halteres pale, knobs brown ; feet yellowish ; knees, 

 tips of tibiae, of the first" joint of tarsi and of their last joints brown. Abdomen 

 brown; posterior margins of segments paler. Wings whitish, with brown 

 spots and bands : most of the spots have the form of a ring, with an infus- 

 cated vein in the centre ; they are distributed in three groups : 1st, basal 

 group, formed of an ocellus near the origin of petiole, a spot in the subcostal 

 area and two rings at the basis of the wing, near the basal angle ; 2d, central 

 band, formed of four ocelli and a large brown spot near the posterior margin ; 

 3d, apical band, formed of two large ocelli (at the tip of the discal areolet and 

 at the origin of the radial fork) ; 6 or 7 smaller ocelli along the apical margin 

 of the wing and a brown band, beginning between the two large ocelli, and 

 running along one of the longitudinal veins towards the tip of the wing. 



I am in doubt as to the sex of the two specimens of this insect, for which I 

 am indebted to Dr. Asa Fitch. 



BlTTACOMORPHA WestW. 



I take occasion to give the figure of the male genital organs of B. c 1 a vi p e s 

 Fab. (fig. 33, from above ; fig. 33a from below.) One pair of appendages (the 

 outer ones), are coriaceous ; the shorter, inner pair seems to be of a harder 

 consistence. 



This species seems to have a wide distribution over the North American con- 

 tinent. The British Museum has received it from Nova Scotia, (see Walker's 

 List of Dipt. Brit. Mus. i. p. 81). I found it in Florida, and possess, besides, 

 specimens from Upper Wisconsin River. It occurs early in the spring, and 

 also in autumn, in woods, in the neighborhood of running water. 



Ptychoptera Fabr. 



For the characters of this genus I refer to Meigen, Zetterstedt and Walker, 

 and will only mention, as a character which is peculiar to Ptychoptera, 

 Bittacomorpha and Protoplasa, and which seems to have been over- 

 looked, that the transverse thoracic suture is deeply sinuated, so that the scutum is 

 attenuated in the middle, its two lobes being connected by a narrow band only. 

 The only American species I possess is very like the European species of 

 this genus in general appearance, without seeming to be identical with any. 



P. rufocincta. Nigra, abdomiue (<?) maculis lateralibus apiceque fer- 

 rugineis, pedibus ferrugineis, alis macula basali et fasciis tribus fuscis ; long, 

 lin. 3f . . 



Head black, shining ; proboscis and two basal joints of the black antennae 

 ferruginous ; palpi pale. Thorax black, subopaque ; pleurae, with ferrugi- 

 nous spots and bands, and with a silvery reflection along the coxae, and 

 especially under the base of the wing ; halteres pale ; tip of the knob dusky ; 

 feet pale ferruginous ; tips of the femora, of the tibiae and tarsi, brown. 

 Tergum black, shining ; large ferruginous spots on the lateral margin of the 

 2d and the following segments ; they occupy a large portion of the anterior 

 part of the intermediate segments ; tip of the abdomen and genitals (?) fer- 

 ruginous ; venter tawny. Wings with a brown spot at the base ; an abbre- 

 viated band about the middle of the praebrachial and pobrachial areae, between 

 the subcostal and pobrachial veins ; a second band along the central cross- 

 veins, attenuated behind, and not reaching the posterior margin; a third is 

 formed of two spots at the origin of both forks ; a brown dot at the tip of the 



[Aug. 



