228 RESEARCH IN CHINA. 
and forward to a little below the center and arches around a rather large, depressed 
central space, terminating a short distance before completing a circuit of the space; 
between the ridge described and the hinge-line are two spaces outlined by the main 
ridge; of these the one nearest the anterior cardinal angle is somewhat depressed 
and outlined by a shallow furrow extending at right angles to the hinge-line from 
the ridge to the hinge-line. At a point about two-thirds the distance of the length 
of the hinge-line a short and very slight ridge extends toward the hinge-line from 
the main ridge; between this and the slight furrow there is a slightly convex area. 
Two minute tubercles occur on the long central ridge, one at the point where it 
begins the loop to inclose the depressed central space and the other on the opposite 
side of the depressed space. 
Surface minutely punctate under a strong lens. 
Entire width of valve, 2 mm.; length, 1.25 mm.; depth, about 0.5 mm. 
This species is distinguished from Aluta sterope [p. 227] by its wider valve and 
the presence of the central ridge and depressed space. 
The specific name is given in recognition of the excellent and thorough pre- 
paratory work that was done by Miss Elvira Wood in the preliminary study of the 
Cambrian fossils from China and her work upon the Devonian crinoids. 
Formation and Locality —Middle Cambrian: (C32) A fine-grained bluish-black 
limestone bowlder believed to have come from the lower part of the Ki-sin-ling 
limestone [Blackwelder, 1907¢, p. 272]; collected in river drift 1 mile (1.6 km.) south 
of Chén-p’ing-hién, on the Nan-kiang River, southern Shen-si, China. 
Collected by Bailey Willis and Eliot Blackwelder. 
MEROSTOMATA. 
Genus AMIELLA Walcott. 
Amiella WaLcorT, 1911, Smithsonian Misc. Coll., vol. 57, No. 2, p. 27. (Described and discussed 
as a new genus.) 
Amiella yunnanensis Mansuy (MSS). 
After the printing of the paper on Middle Cambrian Merostomata,' I received 
under date of March 22, 1911,’ a letter from Dr. H. Mansuy, geologist of Indo- 
China, in which he stated that he had proposed the specific name yunnanensis for 
the merostome associated with Redlichia chinensis. Doctor Mansuy also sent a 
photograph of the illustration which will appear in his forthcoming report. 
ISmithsonian Misc. Coll., vol. 57 NOw2 eLO Li. 
"Received at Washington in May, rgr1. 
