NO. 1105. PROCEEDINGS OF THE NATIONAL MUSETM. 199 



all of the genital glands. The cirrus pouch and vagina could not be 

 studied in detail; the former is very small and muscular, and measures 

 0.14 mm. long by 44 /t broad. Excretory and nervous systems could 

 not be analyzed. 



These are all the details which can be given for the type specimen, 

 but from some of the other material the following could be observed: 



The vagina is distal of the cirrus pouch. The muscular layer of the 

 cirrus pouch measures up to 20 u thick. The cirrus when retracted 

 forms several coils in the pouch, but no vesicula seminalis could be 

 distinguished; in fact there is no room for one within the pouch when 

 the cirrus is retracted. The egg capsules fill the entire median 

 field of the segment, and occasionally extend into the lateral fields; 

 there are about 160 visible upon one face of a segment; they are 

 globular in form, but assume various shapes by reciprocal pressure; 

 they measure 0.112 to 0.128 mm. in diameter and contain 3 to 15 ova; 

 the ova measure 20 to 24 /* in diameter. 



The posterior 10 to 20 segments decrease in breadth and increase in 

 length very rapidly, in some cases measuring 1.8 mm. broad by 1.4 mm. 

 long. 



In some specimens the pores show a remarkable tendency to 

 unilaterality; in fact, in two specimens which Dr. Norgaard has col- 

 lected since this article was written all of the pores are on the same 

 side of the worm. The position of the genital pore is evidently a very 

 uncertain character in the genus Davainea. 



Further details are not warranted by the material at hand. 

 * As a name for this parasite, I proposed Davainea salmoni, dedicating 

 the species to my friend and chief, Dr. Daniel E. Salmon, Chief of the 

 Bureau of Animal Industry, United States Department of Agriculture, 

 to whose broad policy of administration 1 am indebted for the opportu- 

 nities of carrying on my work in helminthology. 



The larval stage. In December, 1887, Cooper Curtice examined a 

 rabbit (Lepus sylvaticus) in which he found a numb.er of tapeworms 

 in various stages of development. He made an extremely important 

 observation on the younger specimens, which, unfortunately, he never 

 published. 



In Science, 1 however, the following notice concerning Curtice's obser- 

 vation is found: 



EARLY STAGES IN THE LIFE OF T^ENIA PECTINATA. 



Thousands of sheep and lambs perish every winter on the ranches west of the 

 Missouri Kiver. They are not apparently afflicted with any disease. They are weak 

 and lean in the fall, and simply seem to be unable to withstand the severity of the 

 blizzards. The Bureau of Animal Industry of the Agricultural Department has been 

 engaged in an investigation to ascertain, if possible, the cause of the weakness of 

 the animals that perish, and Mr. Cooper Curtice visited the West in the prosecution 

 of this work. An examination of the viscera of slaughtered sheep and lambs, fat 



1 March 23, 1888. 



