RESEARCHES IN HELMINTHOLOGY A.ND PARASITOLOGY. I43 



motionless cilia, while other actively contracting individuals pos- 

 sessed no trace of these appendages. Some of the Gregarines further 

 exhibited transition stages towards transformation into uavicella- 

 cysts. The latter differed from those previously mentioned in having 

 but a single thin membranous la5-er for their wall instead of many 

 layers. 



Prof. L. added that our earthworms, which appear to be the same 

 as the common European species, likewise appear to be infested with 

 the same variety and kind of parasites. Among the latter he had 

 repeatedly observed the infusorian Aiioplophrya lumbrici, and also 

 several different nematoids. One of these, which he had found in 

 the sperm vesicles, appeared to be undescribed. It was certainlv 

 different from the Dice/is Jilaria found in the same organs by Dujardin. 

 It appears nearly related with Anguillu/a, and ma}^ be regarded as 

 such with the name of A. melancholica . Its characters are as follows : 

 Body cylindrical, tapering at the ends, distinctly annulated. Head 

 truncated, with the vertex convex, and perforated centrally by the 

 mouth, and defined from the sides by an elevated annulus. Tail 

 conical, and ending in a short, thick conical process. Mouth a minute 

 round pore, unarmed ; pharynx a short narrow tube ; oesophagus 

 long, cylindroid, widening posteriorly, and rather abruptly narrowed 

 at the anterior extremity ; gizzard wider than the oesophagus, cylin- 

 drical and rounded at the extremities ; intestine straight, intensely 

 black or blackish brown. Length from 3 to 4 millimeters ; thickness 

 at middle 0.15 m. Length of oesophagus 0.5 m., of gizzard o. 1 25 m. , 

 thickness 0.075 ^^^-^ thickness of intestine 0.05 m., length of tail 

 from anal aperture 0.175 m. Color black, with the anterior end 

 white. All females. Sometimes upwards of a dozen found in the 

 sperm vesicles of a single earthworm. 



[May, 1877. No. 440. See Bibliography.] 



On Flukes Infesting Mollusks. — Prof. Leidy remarked that our 

 common fresh-water mollusks, especially the gastropods, were much 

 infested ^\\.\v flukes. These appear to be prevalent during the latter 

 part of the year, and absent during the earlier part. Drawings were 

 exhibited of the sporocysts and cercariae of two species of flukes in- 

 festing Plaiwrbis parvus. 



The species were named and described as follows : 

 Mo7iostoma {Glenocercaria) Lucania. Sporocyst bright orange-col- 

 ored, cylindroid in form, with obtusely rounded extremities. 

 Pharynx globular, from which is suspended a long cylindrical 



