i 4 - CRUSTACEA OF ALABAMA. 



marine form has as yet been reported from America. The species of Cyclops identi- 

 fied from Alabama are the following, for descriptions of which the reader is referred to 

 the writer's Final Report, or a more inclusive work soon to appear. 



i. Cyclops ater, Herrick. The most characteristic southern species and expressing 

 the extreme of compactness. 



2. Cyclops viridis, Jur. common. 



3. Cyclops parcus, Herrick. 



4. Cyclops thomasi, Forbes. 



5. Cyclops modestus, Herrick. 



6. Cyclops semilatus, Fischer. 



7. Cyclops elegans, Herrick. 



8. Cyclops fiiiviatilis, Herrick. 



9. Cyclops diaphamis, Fischer. 



10. Cyclops plialeratus, Koch. 



12. Cyclops fimbriates, (= crassicornis) Fischer, (Plate VII, Fig. 2.) 

 (See C. simplex below.) 



The following descriptions are appended in order to sharply define those species 

 especially characteristic of the southern fauna. 



Cyclops ater. Herrick. 



" This is our most striking species and loves the clearer flowing waters. The thorax 

 is broadly oval and, usually, of a deep color. Antennse as long as the cephalothorax 

 (1.2 mm.), slender, and tapering toward the end; last three joints rather short, the last 

 joint furnished with an unserrated knife-like ridge as in C. tenuicornis ; maxillipedes 

 rather large ; fifth foot one-jointed, armed with three subequal spines ; abdomen rather 

 short, last segment especially short; stylets of moderate length; setae rather short, inter- 

 nal seta much longer than the outer, lateral seta situated near the end of the stylet ; 

 eggs pale. Color deep blue or gray. Length 2.1 mm. The young can be recognized 

 without a glass by the band of deep color which crosses the thorax in the middle." 



This species has been collected in different parts of the Mississippi valley from Ala- 

 bama to Minnesota, but is nowhere very abundant, being rather more so southwardly. 



Cyclops modeStUS, Herrick. 

 American Naturalist, 1883, p. 500 (May.) 



This small species, 1.0 mm. long, was first recognized in Cullman county, Alabama, 

 but occurs also in our lakes. The color varies, but very characteristic is the peculiar 

 shining or glaucous surface of the strongly arched thoracic shield and the evenly curved 

 segments of the abdomen. The antennae reach but little beyond the very long first seg- 

 ment ; they are usually 16-jointed, but I have notes of a similar form in which the an- 

 tennae are 17-jointed. The rami of the feet are all 3-jointedand are peculiar in their ar- 



