348 Forty-sixth Report on the State Museum 



rather loDg legs, and other thread-like terminal organs. " They are 

 not occurring abundantly at the present time, but usually in the autumn 

 small ones of the same general appearance are quite numerous." 



The gentleman sending them desired to know what they were, and 

 their source, as he feared that they might render the water unfit for 

 domestic use. 



It proves to be an interesting species of fresh-water shrimp which 

 occurs only in such unusual localities as wells and subterranean streams. 

 Like the blind craw-fish of the Mammoth Cave of Kentucky, to which 

 it is closely allied, it is entirely destitute of eyes. It was first discov- 

 ered by Professor S. A. Forbes, State Entomologist of Illinois, in a 

 well at Normal, III., and was named and described by him, in Bulletin 

 JVo. 1 of the Illinois Museum of Natural History, December, 1876, 

 page 21. It belongs to the Order of Amphipoda and to the Family 

 of Gaminaridm. It is described as follows, — combining the generic 

 characters with ihe specific: 



C. mucronatus Forbes. ISJ'o eyes [a congeneric species, gracilis, has 

 eyes]. Peduncles of the two pairs of antennae subequal. Hind angles 

 of first three abdominal segments rounded; no clusters of spines on 

 posterior abdominal segments. Last pair of abdominal legs with inner 

 branch minute, outer branch shorter than peduncle; the first two pairs 

 of feet subequal. Telson single, of male a slender spine about as long 

 as fir?t three abdominal segments. 



Illustration is given of structure in seven enlarged figures. 



Professor Forbes informs me that the above is the first instance in 

 which this crustacean has been reported from east of Indiana. It is 

 not confined to wells, but it has been frequently found in certain 

 springs in seasons of high w^ater when the soil is saturated; it also 

 often comes to the surface at the mouth of drains, but as it is entirely 

 subterranean, it does not live for any length of, time in surface waters. 



In explanation of its occurrence in drains. Professor Forbes has 

 kindly written me: " The drains referred to in my letter are ordinary 

 farm drains, but as the Crangonyx and its companion crustacean, 

 Asellus stygius, do not occur in such drains indiscriminately, but only 

 in here and there one, I presume that their appearance in such situ- 

 ations is due to the presence of springy ground aud a penetration of 

 the tiles by the subterranean crustaceans from some underground 

 source." 



The publication of the occurrence of the Crangonyx at Oswego, in 



the Albany Eveyiing Journal of March 27th, 1891, and in the Neio York 



Times, brought to light other localities in the S:ate of New I'ork and 



elsewhere where it was also to be found. Referring to the Times^ 



