THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL. 



YoL. VII. Washington, D. C, Septembek, 1886. 'No. 9. 



A Parasite of Porcellio. 



BY W. F. DURAND,ASST. ENG.,U. S. N. 



The parasite figured in the accom- 

 panying sketch was found in a speci- 

 men of Porcellio spinicornis taken 

 from a decaying pine stump in the 

 spring of the present year. The 

 length of the Porcellio was about 

 .4 of an inch, the length of the par- 

 asite about .3 of an inch. It occu- 

 pied the whole of the abdominal 

 cavity, which was much distended 

 beyond its normal size. 



Its body seemed to consist of a sac 

 elongated and tapering at each end, 

 without external ap- 

 pendages. Its mode 

 of progression was 

 bv a series of ryth- 

 m i c contractions 

 and extensions of 

 the outer integu- 

 ment, accompanied 

 by corresponding'' 

 changes of form and 

 puis ations of the 

 body contents. 



At ^was a kind 

 of cylindrical, 

 transparent head, 

 furnished at A and 

 B with two little 

 horn-shaped p r o - 

 cesses, with a sug- 

 gestion of a knob 

 on the end. Fol- 

 lowing these back 

 they were f o u n d 

 to be the ends 

 of two tracts extending the entire 

 length of the body, and terminating 

 with very similar extremities at A' 

 and B . At C and E these tracts 



gave ofi^ each a branch, which be- 

 came united at D. At F was an 

 arch connecting BB' with ED' . 

 The structure of these tracts seemed 

 to resemble somewhat that of tra- 

 chea in insects. 



In addition to the larger tracts or 

 vessels spoken of above, there 

 seemed to be an extensively rami- 

 fied system of smaller vessels, ex- 

 tending in all directions through the 

 outer integument or just beneath it. 



At ^ was a kind of cylindrical 

 opening with two reddish spots just 

 inside, at the ends of two dark pro- 

 cesses, continuing into the body cav- 

 ity. Both this and the so-called 

 head at //were retractile at will. 



[We regret that we are unable to 

 furnish any information as to the 

 creature above described. Mr. 

 Durand found but a single specimen, 

 a sketch of which he referred to 

 Prof. Leidy, the original, killed and 

 much distorted under examination, 

 being unfit 'for preservation, but -it 

 was entirely unknown to him, and 

 in his letter he says he does not even 

 feel sure to what group it belongs. — 

 H. L. 0.] 



o 



American Society of Microscopists. 



The ninth annual meeting of the 

 American Society of Microscopists 

 was held at Chautauqua on the loth, 

 nth, 1 3th, and 13th of August, a 

 very full attendance of members be- 

 ing present, the interest in the pro- 

 ceedings well sustained, and a large 

 accession of new members received. 

 The Society appears to be flourishing 

 and to be gaining the support and 

 encouragement of microscopists gen- 



