144 RESEARCH IN CHINA. 



gradually increasing in width toward the center, where it is slightly convex, and 

 marked at the center by a minute, sharp tubercle ; dorsal furrow strong and rather 

 deep about the glabella. 



Fixed cheeks about the same width as the glabella, moderately convex; they 

 slope gently from the dorsal furrow to the palpebral lobe, and backward to the fur- 

 row of the postero-lateral limb ; in front they slope rather rapidly and merge into the 

 frontal limb; palpebral lobes small and situated about their own length from the 

 posterior margin of the cephalon; palpebral ridge very faint, scarcely perceptible 

 except by turning the specimen in the light; frontal limb slightly convex, sloping 

 gently downward, and divided midway by a longitudinal furrow that extends from 

 the front of the glabella to the furrow within the frontal rirn ; each side of the longi- 

 tudinal median furrow the frontal border extends outward and backward, merging 

 into the fixed cheeks without any interruption in the convexity of the slope ; frontal 

 rim narrow, nearly flat, and separated from the frontal limb by a very shallow 

 groove which is little more than a change in slope of the frontal limb to the nearly 

 flat frontal rim; postero-lateral limbs very short. 



Surface minutely granulose under a strong lens, with a few scattered, larger 

 granules. 



The largest cephalon of the species in the collection has a length of 4 mm., with 

 a width at the palpebral lobes of nearly 5 mm. 



This species is characterized by the longitudinal furrow in front of the glabella, 

 which resembles the longitudinal furrow frequently seen in the frontal limb of the 

 cephala of Agnostus. 



Doctor Monke describes and illustrates a free cheek and two pygidia that he 

 assigns to this species. He does not make comparisons with other genera, as he evi- 

 dently planned to refer the genus again in a future contribution to the subject. 



Formation and Locality. Middle Cambrian: (C'6) Thin, platy limestone in the 

 upper shale member of the Kiu-lung group [Blackwelder, 19070, pp. 37 and 41 (sec- 

 ond list of fossils), and fig. 10 (bed 12), p. 38], 2.5 miles (4km.) southwest of Yen- 

 chuang, Sin-t'ai district, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Doctor Monke 's specimens occur on slabs of limestone at Yen-tsy-yai, in 

 Shan-tung. 



Also from Middle Cambrian: (3(5 f) Fu-chou series, about 1,000 feet (305 m.) 

 above the white quartzite [see Blackwelder, 1907^, p. 92, for general stratigraphic 

 relations], collected in a low bluff on the shore of Tschang-hsing-tau Island, east of 

 Niang-niang-kung, Liau-tung, Manchuria, China. 



Collected by J. P. Iddings and Li San. 



Genus PROAMPYX Freeh. 



Proampyx FRECH, 1902, I.ethsa geognostica, pt. i, Letha?a palsozoica, No. 2, p. 66. (Genus defined 

 and discussed essentially as below.) 



Dr. Fritz Freeh proposed the genus Proampyx for Anomocare acmmnatiiiu 

 Angelin [1854, edition of 1878, p. 26, plate 18, fig. 7] on account of the projection of 

 the frontal border into a strong spine. He said [1902, p. 66] : 



"The peculiar, very variously formed group of Anomocare acuminatum with 

 pointed glabella, seems to be the forerunner of Ampyx and is called Proampyx. 

 The difference from the typical A nomocare with rounded cephalic shield is striking. 

 The separation of the genus Proampyx from the typical Conocephalidae follows from 

 the transitional forms Arionellus sulcatus [AngeUn, pi. 18, fig. 6] and A. dijfformis 



