Sapphirina sp. 



434 Sidney I. Kornhauser 



The chromosomes were seen only in the spenua« 

 togenesis. In the spermatogonia are 16 — in 

 size a graded series from larger to smaller. 

 Though the chromosomes are much smalJer than 

 in Hersilia, a "Querkerbe" is often plainly 

 visible. In the bouquet stage of the spermato- 

 cytes, the presence of a nuclear cap and nucleohis 

 reminds one a great deal of the same stage in 

 Hersilia. The maturation divisions also greatly 

 .resemble those in Hersilia. K. 



In the Cyclopoida our data is limited to the genus Cydops and three 

 species belonging to three different families somewhat distantly removed 

 from the Cyclopidae. In this group the chromosome niimber varies from 

 twelve to two, and the average number is seven. Besides the ditetrads 

 the frequent presence of small paired or unpaired hetero-ehromosomes 

 usually withoiit '"Qnerkerbe is notable. In the germinal vesicle and in 

 the first maturation spindle of Cyclops, the di-tetrads are in the form 

 of parallel rods; and in the cleavage stages the chromosomes are long, 

 in the form of V's or U's. 



Cyclops phaleratus, a form which, in its structure, resembles 

 the genus Canthocmnphis and is looked upon by Schmeil ('92) as 

 a connecting link between the families Cyclopidae and Harpactidae, 

 is an interesting species. The maturation division has been de- 

 scribed by Matscheck ('10), who showed that the form of the 

 chromosomes is more like the other Cyclopidae, but that the manner 

 of fonning the polar bodies is exactly like that of the Harpactid, 

 Canthocamptus. 



Hersilia, Lichomolgus and Sapphirina must not be looked upon 

 as close relatives of the Cyclopidae. They are all marine f orms ; the first 

 two, semi-parasitic ; and the feniale of Sapphirina is usually found Avithin 

 Salpa as a commensal or parasite. Hersilia shows certain resemblances 

 to the Cyclopidae; the chromosomes, before entering the spindle of the 

 primary oöcyte, are composed of two parallel rods (Fig. 48, PI. VI). 

 This form may be kept in the metaphase (Fig. 51 ; Fig. 50 right hand 

 side), or the pairs may form rings in condensing, resembhng those of 

 the Calanids. In the cleavage stages the chromosomes of Hersilia are like 

 those of the Cyclopidae, not short and plump like those of the Calanidae, 

 The spermatogenesis of Sapphirina is, in a great many respects, like 

 that of Hersilia. The similarity in the form of the chromosomes, the pres- 

 ence of a nuclear cap and nucleolus may indicate a relationship between 

 the Hersiliidae and the Coiycaeidae. 



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