135 



A New Habitat for Gastrophilus. By A. W. Bitting. 



The genus Gastrophilus contains two well known species, Gastrophilus equi 

 and Gastrophilus haemorrhoidalu'. These parasites are commonly known as bots 

 and inhabit the stomach and duodenum of the horse. 



The life cycle is as follows : The female deposits her eggs upon the ends of 

 the hairs upon the fore limbs or some other part of the body that the horse 

 is likely to touch with his mouth in fighting flies. The eggs hatch and the lid 

 breaks open to permit their escape in from five to fifteen days. They attach 

 themselves to the lips or tongue when the host is fighting flies and soon find their 

 ■way into the stomach or interior part of the duodenum. Here they pass a period 

 of development lasting about seven months. Their food consists of the nutri- 

 ment found in solution iu the juices of the stomach. They escape from the body 

 with the excrement, pass a pupa state in the ground to emerge in a short time as 

 adult. 



The particular observation to be recorded here is the finding of this parasite 

 in the alveoli of the horse's teeth. 



Last September there were an unusual number of cases of caries of the teeth 

 at the clinics. 



While extracting teeth six larvae were obtained attached to the tissues of 

 the teeth or alveolar cavity. They were alive and active. They were about three 

 centimeters from the surface of the gums and there was no visible point for 

 entrance. 



The question remains how did they get to their destination and how did 

 they accommodate themselves to take nutriment from the blood wlien it is believed 

 that they are dependent upon the juices of the stomach? 



Are they a factor in produciiig caries of the teeth? 



Second Costribution to a Knowledge of Indiana Mollusca. By R. Ells- 

 worth Call. 



The sources of information on which the facts stated in this brief paper are 

 based are various. Iso single source has availed largely in determining the 

 locality references that are given, though the collection in the Geological Museum, 

 in the State Capitol, has furnished the greater number. All the rest have been 

 contributed by specimens submitted through several gentlemen practically inter- 

 ested in the work of the biological survev of the State. For this aid thanks are 



