390 GARRISON. 



others. The careful measurement of fifty ova in the fresh stool gave the 

 following results, in microns': 



99.9X59.2 92.5X02.9 99.9X55.5 92.5X66.6 



90.2X59.2 103.6X59.2 90.2X59.2 92.5X00.0 



99.9X74. 103.0X59.2 99.9X59.2 92.5X53.5 



103.0X62.9 103.6X62.9 103.6X62.9 103.6X62.9 



114.7X55.5 99.9X59.2 99.9X59.2 98.0X59.2 



92.5X55.5 90.2X74.0 ■ 103.0X02.9 103. XG0. 



99.9X60.6 111.0X62.9 90.2X62.9 103. X62.9 



103.0X62.9 114.7X00.6 92.5X59.2 103.6X53.5 



88.8X62.9 99.9X02.9 90.2X62.9 107.3X59.2 



107.3X59.2 96.2X59.2 111.0X81.9 96.2X57.4 



99.9X55.5 99.9X81.9 99.9X59.2 94.3X53.5 



96.2X62.9 92.5X62.9 92.5X59.2 



96.2X59.2 96.2X59.2 92.5X59,2 



Maximum dimensions: Length, 114.7; breadth, 81.9 /*. 



Minimum dimensions : Length, 88.8; breadth, 53.5 /*. 



Average dimensions: Length, 99.58; breadth, 53.5 ,u.. 



When the stools, were repeatedly sedimented until their fascal charac- 

 ter was destroyed, the ova, in about 10 days, developed ciliated mira- 

 cidia which, raising the operculum, escaped from the shell and swam 

 free in the water. Attempts were made to infect several varieties of 

 snails and one variety of fish with the free miracidia, but without success. 



Upon the basis of the characters above described, it is proposed to 

 establish a new genus and species in the family Fasciolidas, of which these 

 specimens shall be the type and for which we propose the names Fascio- 

 letta ilocana. 



FASCIOLETTA gen. nov. 



Generic diagnosis. — Fasciplidce: Body small, elongate, broader anteriorly 

 than posteriorly. Acetabulum near and much larger than oral sucker. Intestinal 

 tract with short, broad prepharynx, highly developed pharynx, short oesophagus, 

 and long, unbranched cffica, which pass along lateral margins and extend to near 

 the caudal extremity of worm. Excretory system consists of a posterior median 

 stem which, posterior to the testicles, divides into two laterally placed canals 

 which extend anteriorly, separating the testicles, shell gland, ovary and uterus 

 from the cseca and vitellaria. Genital pores anterior to acetabulum. Male 

 organs: Testicles massive and compact situated one directly behind the other, 

 in the median line, in posterior portion of body, both caudad of transverse vitello- 

 duct. Cirrus and cirrus pouch highly developed. Female organs: Ovary com- 

 pact, unbranched, situated slightly to right of median line at about the equator 

 of body. Receptaculum seminis absent, Laurer's canal present. Vitellaria most 

 highly developed, in posterior one-fifth where superficially they spread over 

 the dorsal and ventral surfaces, more or less completely encircling the body. 

 Anterior to the caudal border of the posterior testicle they are confined to the 

 lateral fields, conforming closely to the lateral margins of the body, external to 

 the intestinal ea;ca, and reach a position considerably cephalad of the ovary. 



3 Measurements made with Zeiss objective D D (9237), correction collar at 

 20, micrometer ocular No. 3, tube length 145. 



