Miscellaneous. 435 



upon the end of the solid chitinous cone, as determined by re- 

 moving the layer of pigment with dilute potash, and treating the 

 section with acetic acid and then staining with picro-carmine. So 

 far as we can ascertain, no Arthropod eye is so simple as that of 

 Limulus. Our observations have been based on a study of the 

 structure of the lobster's eye from preparations of very great 

 beauty and delicacy, kindly made for us by Norman N. Mason, 

 Esq., of Providence, who has also made beautiful sections of the 

 Limulus-eye, after treating them in various ways. The question 

 as to the nature of the solid cones we are not yet prepared to settle. 

 Are they crystalline lenses or only analogous organs ? Can the 

 horseshoe crab distinguish objects ? We doubt if its eyes enable it 

 to more than distinguish between the light and darkness. Since 

 the above remarks were put in type, we have seen Grenacher's 

 great work on the eyes of Arthropoda. He regards the conical 

 chitinous minie-ball-like bodies as corneal lenses. He does not 

 describe the simple eye, which is a close repetition of one of the 

 corneal lenses of the compound eye of the same animal, except that 

 the lens is shorter and with the end much more obtuse. — American 

 Naturalist, March 1880. 



Fossil Crawfish, from the Tertiaries of Wyoming. 

 By A. S. Packard, Jun. 



Two specimens of fossil crawfish quite well preserved have been 

 kindly lent us for description by Professor Leidy, who received 

 them from the fish-beds of the western border of Wyoming, through 

 Dr. J. Van A. Carter, of Evanston, Wyoming. Of the two speci- 

 mens the smaller presents a dorsal, and the larger a lateral view, 

 both being slightly distorted by pressure ; the length of the smaller 

 from the tip of the rostrum to the end of the telson is 38 millims., 

 and of the larger 53 millims. They do not differ generically from 

 existing species of Cambarus, though with some resemblances to 

 Astacus ; but as the gills are not represented it is not possible to say 

 to which of these two genera the species belongs ; still the weight 

 of characters ally it nearest to Cambarus affinis, as seen in the long, 

 narrow, pointed rostrum, and the form of the chelae and the second 

 antennal scales. These scales are also much as in C. obesus, var. 

 latimanus and Bartonii, but rather narrower, the lateral terminal 

 spine being long, slender, acute. The flagella of the second 

 antennae are of the usual size, extending to the terminal fourth of 

 the abdomen. The distal end of the scape of the first antennae 

 reaches to near the end of the last joint of the scape of the first pair, 

 the species in this respect being more like Cambarus than Astacus. 

 The carapace is of the proportions of living species of Cambarus. 

 The first pair of legs are rather shorter and stouter than in our 

 living crawfishes, and the chelae are rather shorter ; while the 

 surface of the carapace and legs is much more coarsely tubercu- 

 lated than in our Cambari, and in this respect resembles large 

 specimens of Astacus fiuviatilis of Europe, though the tubercles 

 are larger. 



