166 General Notes. 
the species of the Monticuliporoid corals of the Hudson River group. 
They admit two genera, Monticulipora and Ceramopora, the former 
with the sub-genera Dekayia, Constellaria and Fistulipora. 
DeEvontan.—Prof. Calvin (American Geologist) describes Strep- 
tindytes acervularie, a new species and genus of tubicolar Annelida 
from strata of the Hamilton period, at Robert’s Ferry, Iowa. 
CARBONIFEROUS.—Dr. G. J. Hinde, in a paper read before the 
British Association at Manchester, brings evidence in support of 
the organic origin of the “chert” in the carboniferous limestone 
series of the British Isles. He believes that the Irish cherts at 
least are derived from the accumulation of the skeletal elements 
of the siliceous sponges. 
Jurassic.—Prof. H. G. Seeley has shown, by superimposing a 
figure of the reputed clavicle upon the bone figured by Mr. Hulke 
as clavicle and interclavicle of Iguanodon (Quart Journ. Geol. 
Soc., vol. xli. pl. xiv.) that the supposed sutures are fractures, and 
that the supposed interclavicle has no existence, except as an ossifi- - 
cation posterior to the reputed clavicles. Prof. Seeley urges the 
analogy of these bones with the reputed pubes of crocodiles, and 
concludes that they are pre-pelvic. 
Prof. Seeley concludes, from examination of fcetal Plesiosauri 
found in a phosphatized nodule of Lias, that the Plesiosaurus was 
viviparous, and that the species in question, probably P. homo- 
spondylus, produced many young at a birth. 
Tertiary.—R. Lydekker (Geol. Mag., July, 1887) states that 
all the so-called fossil Alligators of the Old World really belong to 
the genus Diplocynodon, and since the crocodiles (C. palustris and 
C. sivalensis) which approach nearest to this genus in the structure 
of the cranium and form of the maxillo-premaxillary suture on the 
palate are confined to India, it becomes interesting to know 
whether the existing alligator recently described from China, may 
not show signs of affinity with Diplocynodon. 
Mr. Lydekker concludes that Crocodilus ehampsoides and C. 
toliapicus, from the London clay, are but the young and old indi- 
viduals of a single species, for which the original name of C. spen- 
ceri Buckland, should be retained. 
H. B. Geinitz identifies Nautilus alabamensis Morton, and N. 
lingulatus von Buch with Nautilus ziczag Sowerby, and places the 
form in the genus Aturia. The species is from the Tertiary of 
Alabama and Mississippi. 
