50 



The Caxadiax Field-Xatlralist. 



[Vol. XXV. 



riau, SticJwpus. Another Polynoid is 

 eommeusal with the starfish, Solaster 

 stimpso)ii. 



The jellyfish supply the only examples 

 among the Ccelenterates. The largest jelly- 

 fish found along the coast, Cyanea arctica, 

 has usually one or more species of amphi- 

 pods and sometimes other crustaceans 

 among its tresses. The actinian, Bicidium 

 aqnorea, is found attached to the umbrel- 

 lar surface of Aequorea forskalea and of 

 Thaumantias ceUulana. • This actinian is 

 spoken of as being parasitic but it is not 

 probable that it is so. Finally, in the Po- 

 rifera, the hermit crab, Pagurus hrandti, 

 appears surrounded by the living sponge, 

 Suherites latus. 



In taking up parasitism only ectoparasi- 

 tism will be considered. The Crustacea pro- 

 vide much tilie great^er number of parasitic 

 species. One vertebrate is probably para- 

 sitic. The lamprey, Entosphenus triden- 

 tatus, attaches itself to the salmon and uses 

 it for transportation purposes, but it is 

 scarcely possible that the skin of the sal- 

 mon is so thoroughly pierced for this pur- 

 pose alone. 



One mollusc is apparently parasitic al- 

 though it may be merelj" commensal. This 

 is the species that has been called Lepton 

 rudehy "Whiteaves and Ericyna rugifera by 

 Carpenter, found attached to the surface 

 of the abdomen of the sand shrimp, Eupo- 

 gehia pugettens's. The annelid, Myzosto- 

 ma, is parasitic on the Crinoid, Florometra 

 serratissima. Trematodes are commonlv 



found in the gill cavity of several species 

 of fishes, attached to the surface, and some 

 blood-red nematodes have been found on 

 the clingfish, Caularchus meandiinus. 



The copepods make up a large portion 

 of the list of parasitic Crustacea. There is 

 one parasitic isopod, Phyllodorus abdomi- 

 nalis, common on the abdominal surface of 

 the sand shrimp, Eupogebia pugettensis, 

 and a Rhizocephalan, Sacculina, on diffe- 

 rent species of shrimps. 



Parasitic copepods were discussed in a 

 paper read before the Royal Society of 

 Canada in 1920. Those parasitic on fish 

 are very numerous and of many species. 

 In these there is the greatest variation in 

 the manner in which parasitism has af- 

 fected the parasite. Galigus gurnardi, for 

 instance, shows no great degeneration and 

 is almost as freely moving as non-parasitic 

 forms. It moves readily about on the host 

 and has been found with the plankton 

 where it must have been swimming, freely 

 in the sea. From such a condition there 

 is a gradually increasing degeneration 

 until such a shapeless, helpless mass as 

 that of Chondracanthus or Clavella is 

 reached. 



The only parasitic copepod found else- 

 where than on fish, was a small, red spe- 

 cies (undetermined) whidh is common on 

 the red sand shrimp, Calianassa califor- . 

 niensis. It is quite possible that a more 

 careful observation would bring others to 

 light. 



GLEANINGS FROM THE CANADIAN WEST. — PART I. AVIAN FAUNA 



OF ISLAY, ALBERTA. 



By J. Dewey Soper. 



While af'cumulating the notes embodied 

 in the following pages I felt congratula- 

 ted in my fortune to be again haujiting 

 comparatively unknown fields in this de- 

 lightful science. By unknown fields, of 

 course, I refer to the geography in con- 

 nection wit|» the faunal forms that I 

 mention, not to any original intimacy 

 with the species themfw^lves. The mo.st, 

 apparently, whirA a new region may do 

 for one at this time, barring the extreme 



and improbable fortune of discovering 

 new members of our country's fauna, is 

 to strengthen, correct, or ei?tablish lineis 

 of distribution. All the facts proffered 

 may long since have been known to some 

 one, perhaps even published in papers 

 t^at I ihave as yet overlooked. Never- 

 theless I enjoyed a rare satisfaction in 

 winnowing from the Islay prairies what- 

 ever of interest or value may appear in 

 this article. Here, in this little, isolated 



