211 
[Packard. 
dense and solid crust, and the apparent want of a large broad ab- 
domen, so characteristic of Scyllarus. From the Galatheidce , the 
fossil form differs in having the last pair of legs as large and stout 
as the third and fourth. It cannot be referred to the Hippidce. To 
neither of the extinct mesozoic families Eryonidce and Glyphceidoe 
can our fossil be referred, since the carapace lacks the median ridge 
and the lateral serrations of the former group, and the complicated 
sculpturing of the latter. 
In the shape of the first pair of legs there is a resemblance to 
those of Eryon propinquus of the Solenhofen slates, but the fifth 
pair of feet are much stouter. It perhaps may, when better pre- 
served specimens are brought to light, fall into the Eryonidae or 
Palinuridse. It appears to have no special relationship to the Car- 
boniferous family Anthracaridce. We may give it the provisional 
name of Adelocaris 1 peruviensis. 
Casts kindly taken from the type by Mr. N. N. Mason of Provi- 
dence, have been placed in the Museum of Comp. Zoology, Cam- 
bridge, Mass. Boston Society of Natural History and the British 
Museum, etc. 
II. NOTES ON CARBONIFEROUS ARTHROPODS FROM ILLINOIS. 
The following notes on fossils kindly sent me for examination by 
Mr. W. F. E. Gurley, may be regarded as supplementary to the de- 
scriptions contained in the author’s memoirs entitled, “ On the Syn- 
carida, a hitherto undescribed synthetic group of extinct Malacos- 
tracous Crustacea,” “ On the Gampsonychidse, etc.” ; “ On the 
Anthracaridse, etc.,” and “ On the Carboniferous Xiphosurous 
Fauna of North America,” published in the memoirs of the Na- 
tional Academy of Sciences, in, 1886. 
Belinurus lacoei Pack. A finely preserved specimen in a Mazon 
Creek nodule, is worthy of notice. It shows the inside of the ven- 
tral surface of the integument, the specimen probably being a cast 
skin. The very long genal spine is better preserved than usual ; 
it is very long and slender, reaching as far back as a point in line 
with the eighth abdominal segment, i. e., that next to the ninth seg- 
ment, which forms the caudal spine. It agrees in this respect with 
my description, but not exactly with the restoration (PI. v, fig. 5), 
in which the genal spines are represented rather too wide at the base, 
1 a8r}Aos uncertain; (tapis, a shrimp or prawn. 
