128 RESEARCHEvS IX nELMINTH(JL()(; V AND PARASITOLOCtV. 



tabula are spherical, and opaque white. The diameter of the head 

 is three-fourths of a line. The neck, or unsegmented portion of the 

 body immediateh' succeeding the head, is about 4 lines long by half 

 a line in breadth. The most anterior indistinctly defined segments 

 of the body, and those immediately succeeding them, but more dis- 

 tinctly separated, are about one-fifth of a line long by two-fifths of 

 a line broad. In a more posterior fragment of the bod}- the flat and 

 nearly square segments measure half a line long and a line broad to 

 one-third line long and 2)^ lines broad. A succeeding fragment ex- 

 hibits segments 3 14 lines long by 4 lines broad, and 2 lines long by 5 

 lines broad. Many of the segments in this piece are irregularly sepa- 

 rated, laterally, by deep, wide notches. In a succeeding long portion 

 of the worm the segments are wider behind than in front, and 

 measure 2,5, and 3 lines long by 5 lines broad. In a long piece of 

 the posterior part of the worm the .segments are first 4 lines long 

 and broad, and in the last four feet of the same piece the segments 

 are clavate in outline, from 6 to 10 lines long, and 2 and 3 lines broad. 



The genital apertures are conspicuous, and are situated behind the 

 middle of the segments. They alternate irregularly. Thus, in the 

 last two feet of the posterior fragment of the worm, the first two 

 segments exhibit the aperture on the left margin ; the succeeding 

 segment presents the anomaly of an aperture on both margins, then 

 follow three apertures on the right, next two on the left, then four 

 on the right, then eight alternating in pairs, then one on the left, 

 and so on. The ovaries are opaque white, and exhibit numerous 

 closely crowded lateral branches. 



In the absence of pigment-granules to the head, and in the less 

 robust character of the worm, the specimen differs from 7. medio- 

 cayiellata as described by Kuchenmei.ster. The minute acetabular 

 pit or fovea at the summit of the head is not mentioned by Kuchen- 

 meister and .subsequent observers as a character of that species. It 

 is a point, however, that might be readily overlooked, especialh' if 

 parts of the head are obscured by the presence of pigment-granules. 

 (Drawing.) 



[November. 1871. No. 361. See Bibliography.] 



FLIES AS A MEANS OF COMMUNICATING CONTAGIOUS DISEASES. 



Prof. Leidy remarked that at this time, during the prevalence of 

 smallpox, he was reminded of an opinion he had entertained that 

 flies were probably a means of communicating contagious diseases to 

 a greater degree than was generally suspected. From what he had 



