52 RESEARCHKS IN HELMINTHOLOGY AND PARASITOLOGY. 



upon any part of the exterior of the body of Astacus Bartonii, Fab., 

 but more especially upon the inferior surface and branchise. 



MaLACOBDKLLA, BIvAINVILLE. 



14. Malacobdella Grossa, Blainville. — Hinido grossa Miiller, Zool. 

 Dan. MalacohdcUa grossa, Blain\-ille, Die. Sc. Nat., xlviii, 270 ; Mo- 

 quin-Taudon, Monao;. Hirud. ; Diesing Syst. Helm. ; PJiylliiic grossa, 

 Johnston, Lond. Mag. Nat. Hist., lii, 6-10. 



Body yellowish white, compressed pyriform, oblong or elliptical. 

 Integument translucent. Acetabulum yellowish, circular, ^ths to 

 2)^ or 3 lines in diameter. Protractile proboscis cylindrical, from 

 14 to 3 lines long. Intestine tortuous. Ov^aries upon each side 

 iron gray. 



Length from 2 lines to i inch, occasionally i ^^^ inches; breadth 

 from ^2 a line to 5 or even 7 lines. 



Hab. — Found frequently, usuall}^ singly, adhering to the mantle 

 of \^enus merccnaria, L,in. and \'em(s prcFparca, Say. 



[June, 1851. No. 77. See Bibliography.] 



Dr. Ivcid}' remarked that it had occurred to him whilst examining 

 the mole cricket, referred to at the meeting of May 20, that if the 

 fragments of the insect were placed under favorable conditions, the 

 fungoid matter in the interior of the insect might develop itself into 

 an external form of fungus. He accordingly placed them in a small 

 glass case, with some moist sphagnum, and allowed them to remain 

 until the present time. Dr. L. exhibited the glass case with the 

 fragments, each having sprouted out of it one, two, or three elon- 

 gated, conical stipes of a cream color, from three lines to i inch 

 long, and from 'i to i'2 lines in diameter. Dr. Leidy, continued, 

 in examining insects for entophyta and entozoa, he had found the 

 hemiptera remarkably free from them, which he considers an im- 

 portant fact. Those insects which eat large quantities of vegetable 

 .solid food, especially such as eat decaying substances, are very much 

 infected with parasites. The spontaneous generation of entophyta 

 and entozoa finds but few advocates at the present day. Late re- 

 .searches leads us to suspect that mau)^, if not all, entozoa pass part 

 of their life out of the animals in which they are known as para- 

 sites, under forms different from those when within the animals. 



The entrance of the parasites into other animals is effected prob- 

 ably in two ways : with the food of the latter, or by boring from 

 the exterior. The former method is probably the most frequent in 



