24 Our Fresh-ivater Entomostraca — Chavihers. 



other genus of the same family, Artemiadce, Jones, Brandiipodidce, 

 Baird), is found in brine pits, and Prof. Verrill Qoe cii) describes a 

 species from the Great Salt Lake. Ncbalia is the only extant genus 

 of the allied family Ncbaliadce, of which two genera (Hymenocharis and 

 Cercdiocaru), are found fossil in the Silurian strata. Ajyus, of the allied 

 family Apodidce, is extant, and it, or a closely allied form, has been 

 found fossil in the coal measures. EntomoconcJvm, also of the coal, is 

 considered a Fliillopod by Prof. Owens (Paleontology, p. 42); but Prof. 

 Rupert Jones, from its resemblance to the recent Heterodesvivs (Brady), 

 places it among the Hidocypridce. Ditlmrocaris is a fossil genus of 

 the Apodidce, lAmnadiaddi and Limnefis are recent genera of the 

 family Lhnnadiadie, which contains also Esthcria, recent and fossil, 

 extending back to the Devonian sej"ies. I have met in this locality 

 with a single species of Estlierla, undescribed, I think ; but it may be 

 one of two species recently described by Dr. Packard. 



Six species of this genus, from North America, have been described. 

 When found at all they usually occur in great nunibers, and some of 

 my specimens were given to me by a gentleman who informed me that 

 they were taken in a wagon track or small puddle, where they were so 

 abundant that a dip of the hand would take half a dozen. But the 

 single speciipen taken by me Avas under very different circumstances. 

 In a pond, which, because of its convenience and the multitude and va- 

 riety of microscopic forms it affords, has been my favorite collecting 

 ground, I one day dipped up a specimen in an iron spoon. It surprised 

 me greatly, l)ecuuse I had dipped and dredged in that pond so often 

 and so long that I thought I knew everything it coulil aiford, and had 

 never met with an Edheria; and the most diligent search has failed to 

 reward me with a second specimen. The body and branchiferous feet 

 remind one somewhat of Branchippus, but the resemblance is very 

 general. The eyes are not stalked, and, in fact, scarcely deserve to be 

 called eyes, as they are not even crystaline, but are simply two small 

 pigment spots confluent on the median line of the forehead. The head 

 is produced beneath into a short beak, as in the family Daphnkuhv. 

 The larger antenme are furcate, many-jointed, and armed with long 

 cilia, one branch being shorter than the other; the smaller antennse are 

 very short ; there is no long post abdonien or tail like that of Bran- 

 cJiippus, but the post abdomen is short, and ends in two pairs of spines, 

 one above the other, and each curving upward ; and along the back, 

 toward the tail, is a row of small spinous pr(^jections, reminding one of 

 the vertebrate apophyses, and the branchiferous feet are more numer- 

 ous than in Brcuichippns. But the most marked difference is that 

 Edheria inhabits a small bivalve shell, resembling those of some mol- 

 luscs; and Avhile dredging for another specimen of my Edheria, I found 



