of Entomostracites,finCi gives tlie following description of 

 E. jnmcfatus, p. 32, plate 2, fig. 1, (the lij-gidium only, 

 the head represented and described belongs to Aci- 

 Calymene Blumenbachii, Brong. ' Cauda verrucarum punc- 

 ' tatarum serie triplici," and on p. 33, "The shell of 

 the pygidium is longer than it is broad. Tlie axis 

 (back yoke) is furnished along its middle in a longitu- 

 dinal line with a series of elevated tiibercles, perforated 

 at their apex. The lateral folds (pleurae) also have on 

 each side a very similar series of perforated warts ; from 

 this, Brunnich derived the distinctive name of the 

 species." 



In 1822, the celebrated Alex. Brongniart published 

 his excellent book upon the Fossil Crustacea. This 

 treatise is the first work which points to the generic 

 differences of the trilobites, exhibiting five genera. On 

 p. 14, he describes Cahjmene variolaris, and refers Par- 

 kinson's figure (pi. xvii, fig. 16, vol. iii) to this species. 

 He figures Calymene variolaris, on pi. i, fig. 3a, {Ci'yp. 

 piinctatus) and fig. 3b (C variolaris) . The locality for 

 the fossil represented on pi. i, fig. 3b, is unknown, but he 

 quotes the specimen figured on pi. i, fig. 3a, from Dudley. 

 In his description of the species he says : "We count 

 12 to 13 rings in the thorax." His fig. 3a, however, shows 

 12 articulations in the thorax. If this is his 13 ringed 

 specimen, the author has included the occijiital ring in 

 his numeration. The Q-ypt. variolaris has 11 thorax 

 segments, and the posterior angles of the cephalic shield 

 are not produced into spines. This, in connection with 

 his fig. 3b, and reference to Parkinson, we think clearly 

 indicates his species, Calymene variolaris. The follow- 



