28 



The Canadian Field-Naturalist. 



[Vol. XX Y 



1895). Apparently he did not preserve the 

 specimens, but it is the only fairy-shrimp 

 I have found occurring around here. The 

 female especially is easily distinguished 

 from the other species belonging to this 

 genus, having the ninth and tenth body 

 segments produced into lateral, triangular 

 processes dorsally, probably serving for 

 copulatory purposes. The ovisac is broad 

 and elliptical and contains about a dozen 

 ripe, yellow-brown eggs. When the animal 

 is swimming it is continually moving from 

 side to side, so the eggs roll around inside. 

 The clasping antenna of the male are some- 

 what claAv-shaped with a short swollen 

 basal part supplied with two medio-ven- 

 tral, short spines, and a more slender and 

 longer terminal part with bifid tip. Twice 

 as long, however, are a pair of accessory 

 organs at the base of these antenna; (clas- 

 pers) dorsally, in the shape of broad, lob- 

 ated appendages which we may suppose 

 are used for "tickling", or twisted around 

 the female's body during copulation. The 

 protruding male genitalia is a bifid sack 

 ending in two pointed appendages. 



These fairy shrimps attain a size of 1% 

 em. in May-June, when they are ripe, and 

 vary greatly in color, the females espe- 

 cially having much rose-orange, blue and 

 black-brown pigmentation; but my obser- 

 vations regarding the colors of the many 

 individuals I have examined are too de- 

 tailed to be included here. The paired eyes 

 are dark purple and the tips of the cer- 

 eopods white; the latter color shows up 

 very conspicuously when the animals swim 

 in the water. Of this species I have exa- 

 mined specimens from the following Can- 

 adian localities. 



Montreal West, P. Que., May 5, 1920, A. 

 Willey, coll., adult male and female, the 

 latter with eggs. 



De Grassi Point, Lake Simeoe, Ont., Mav 

 10, 1915 and May 6, 1917, E. M. Walker, 

 coll., 27 adults ,12 males, 15 females, I-I34 

 cm. long. 



Scarborough Junction (Toronto), Ont., 

 June, 1908, A. G. Huntsman, coll., 11 

 adults (5 males, 6 females), li^, 1% em. 

 long (see Natural History of Toronto Re- 

 gion 1913, p. 275). 



Ponds near Bond Lake, Toronto, Ont., 

 (York County), April 10, 1920, A. G. 



Huntsman, coll., (young stages, 3-10 mm. 

 long, immature). 



Around Ottawa I have collected them in 

 temporary pools or canals at various pla- 

 ces, at Hull Park, near Fairj^ Lake, Des- 

 chenes and Tenaga (Gatineau River), on 

 the Quebec side, and at various points (Bil- 

 lings Bridge and Hartwell Locks) along 

 the Rideau River on the Ontario side. 

 Around Ottawa the nauplii hatch soon 

 after tlie melting of the snow and the 

 breaking up of the rivers, and the pools 

 thej' occur in are literally teeming with 

 them. They are found in pools on open 

 fields or pastures as well as in the woods ; 

 already at the end of April they are I/2 

 cm. long and the females carry their light 

 brown eggs in the sack. The smallest num- 

 ber I have seen in one pool is y^ dozen, 

 which were collected on April 20, 1919. I 

 tried to keep a dozen of them, (4 males, 9 

 females) alive in a jar. The next day, 

 however, two of the females and three of 

 the males died; before the first of May 

 the last male and a couple of the females 

 died, during the beginning of May the rest 

 of the females died except one which lived 

 until May 7th. It will thus be seen, that 

 these 'animals are more hardy than is gen- 

 erally supposed, especially the females; no 

 food was given them Avhile they were kept 

 in confinement. I observed, that one se- 

 cond elapsed between two succeeding turn- 

 ings-over of the egg-sack from right to 

 left, or the reverse, when the female is 

 swimming ; the movement is apparently for 

 the purpose of bathing the enclosed eggs 

 in the water passing in and out of the egg- 

 sack. May or June is probably the last 

 month in which they are present in 

 southern Ontario and Quebec ; from July 

 on all the pools in which I have observed 

 them earlier in the summer are dried up 

 and the deposited eggs remain in the bot- 

 tom, probably hatching the following 

 spring. 



Prof. O'Donoghue, of the University of 

 Manitoba, tells me in a letter (June, 1920) 

 that "a species of Branchipus, or more 

 probably an Eiihranchipus ) is fairly com- 

 mon all around Winnipeg, on both sides of 

 tlie Red and Assiniboine Rivers, as a rule 



Probably E. Gelidus. (F. J.) 



