596 



SCIENCE. 



[N. S. Vol. XXIV. No. 619. 



Fig. 2. Front aspect of head of male Artemia 

 franciscana, n. sp., showing eyes, antennae and 

 claspers. 



Artemia franciscana n. sp. (Figs. 1 and 2), 

 Body slender; length of mature females (with 

 eggs) from 6 mm. to 13 mm., males 5 mm. to 

 8.5 mm.; color translucent whitish to dull brick- 

 red; claspers of male with stout median part and 

 elongate, regularly tapering acute-angled terminal 

 part; the suture between second and third seg- 

 ments is wholly lacking (this condition prac- 

 tically breaking down the distinction between the 

 genus Artemia and the genus Branchipus) , and 

 there is no indication by external angle or change 

 in direction of the outer or inner margins to 

 indicate the point of fusion of these two segments 

 (Fig. 1); egg-sac of female as broad as long; 

 caudal appendages longer than broad, longer than 

 in any of the other three known American species, 

 and with scattered hairs all along both sides of 

 each appendage (this character also tends to ap- 

 proach the condition in Branchipus). This 

 species in a way serves to connect the genera 

 Branchipus and Artemia but in all its general 

 habitus and in the shape (very characteristic) 

 of the claspers of the male it is much nearer the 

 described Artemia forms than the Branchipus 

 type. Males, females, eggs and larval stages 

 found abundantly in the salterns (evaporating 

 pools), density 1.08 to 1.24, at Redwood City, San 

 Francisco Bay, in September, 1906. 



As mentioned in the species description, 

 mature specimens, both males and females, of 

 this Artemia vary markedly in size and color- 

 ation. They vary also in degree of activity. 

 All these differences are plainly correlated 

 with the different life-conditions of the crea- 

 tures. The water of San Prancisco Bay has 

 a density of 1,024. Pools of evaporating salt 

 solution of the following densities were ex- 

 amined: 1.06, 1.085, 1.11, 1.137, 1.187, 1.19, 

 1.20, 1.207, 1.23, 1.24. Beyond this density 



the salt is precipitating rapidly. Artemias 

 occur in all these pools from 1.08 on, most 

 abundant, largest and most active, however, 

 in water of 1.11 and 1.13. In water of less 

 density than 1.11 the Artemias are large but 

 not so abundant; in water of greater density 

 they are noticeably smaller, and in the densi- 

 ties of 1.20 and upward they are much smaller 

 and much less active. The color variation is 

 also associated with the density, both males 

 and females in the denser pools being reddish, 

 the females alone reddish in the waters of 

 medium density, and both males and females 

 translucent whitish in the pools of 1.085, 1.11 

 and 1.137. In water of 1.24 (in which the 

 salt is precipitating slowly) there are not many 

 Artemias and they are all reddish, very small 

 and noticeably inactive. 



With special reference to the differences 

 which Schmankewitsch and Anikin found 

 among individuals of Artemia salina grown 

 in salt solutions of various densities I may 

 confine myself, at present (pending the out- 

 come of more systematic observation and ex- 

 perimentation), to the statement that differ- 

 ences in proportional length of post-abdomen 

 to rest of body, in character of the abdominal 

 segmentation and in length and hairiness of 

 the caudal appendages are apparent in this 

 new Ai'temia and evidently bear a definite 

 relation to the different densities of the pools 

 in which the Artemias are living. 



Yernon L. Kellogg. 



Stanford Univeesity, Calif. 



some unusual new jersey fishes: 

 During the past summer Mr. Wm. J. Fox 

 was located at Sea Isle City, N. J., and ob- 

 served or obtained the following species : Lam- 

 na cornubica, Galeocerdo tigrinus, Myliohatis 

 freminvillii, Clupanodon oglinum, Lucania 

 parva, Tylosurus rapMdoma, Hemiramphus 

 hrasiliensis, Albacora thynnus, Seriola la- 

 landi, BlepharicMhys crinitus, Vomer seta- 

 pinnis, Palinurichthys percifotmis, Bairdiella 

 chrysura, Chcetodipteriis fdber, Pomacanthus 

 arcuatus, Balistes carolinensis, Alutera 

 scha;pfii and Echeneis alha-cauda. A fine ex- 

 ample of Istiophorus nigricans was also se- 

 cured, Stephanolepis hispidus and Ortho- 



