174 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii 



Collectors. — J. N. Carpender, A. V. Sliaw. and A. H. White. Cat. 

 No. 28168, U.S.N.M. The American Museum of Natural History has 

 two specimens collected by Mr. R. W. Porter. 



ILLiENUS CRASSICAUDA AMERICANUS (Billings). 

 Illcenus americamis Clarke, Geol. Mimi., Ill, Pt. 2, 1894, p. 714, figs. 20-23. 



One fine enrolled specimen of this well-known species was found by 

 Mr. F. G. Goodridge, of New York City, and was very kindly given 

 to the II. S. National Museum. Mr. R. W. Porter also collected two fine 

 si)ecimens, whicL are now in the American Museum of Natural History. 

 These agree excellently with tliis species, the best examples of which 

 are from Trenton Falls, New York. 



Collectors. — F. G. (ioodridge, J. N. Carpender, A. V. Shaw, and A. H. 

 White. Cat. No. 28167, U.S.N.M. 



ISOTELUS GIGAS De Kay. 



Isotelus r/if/as Clakke, Geol. Minn., Ill, Pt. 2, 1894, pp. 701-706, with text figures. 

 Of this species several fragments were found by J. N. Carpender 

 and A. Y. Shaw. 



DALMANITES (PTERYGOMETOPUS) GOODRIDGII, new species. 

 (Plate -XII, figs. 5, 6.) 



The cephalon of this species recalls that of D.{P.)eboraceus Clarke 

 in the characters of the glabella and in the great prominence of the 

 eyes. However, in J). {P.) goodridgii, the eyes are even more elevated, 

 the cephalon is smooth and devoid of all granulatiou, while the most 

 marked difference is seen in the posterior outline of the head, which is 

 broadly rounded or subquadrate, with a central, short projection. The 

 occipital ring is also much wider, and is strongly elevated medio- 

 posteriorly into an obtuse apex. Of thoracic segments, nine are pre- 

 served in these specimens. 



The pygidium is likewise less triangular than in I>. {P.)ehoraceus, and 

 while there are ten or eleven annulations on the axis, there are not 

 more than five pleurie. These are well developed anteriorly, becoming- 

 rapid ly more and more obsolete. 



Named for Mr. F. G. Goodridge, of New York City, one of the col- 

 lectors of fossils on the Peary expedition of 1897. 



Collectors.— J. N. Carpender and A. H.White. Cat. No. 28170,U.S.N.M. 



CERAURUS PLEUREXANTHEMUS Green. 



Ceraiiriis pleurexanihemus Green, Pal. N. Y., I, 1847, p. 242, pi. Lxv, figs, \a-\n; 

 pi. Lxvi. figs. 1, le-l/i..— Clarke, Geol. Minn., Ill, Pt. 2, 1894, p. 734. 



There are three examples of this species in the collection, none of 

 which are entire, but all agree well with New York specimens. The 

 species did not here attain quite the large size of New York si)ex;imens, 

 but one glabella shows a growth about two-thirds of the largest from 

 the latter locality. 



Collector.— K. H. White. Cat. No. 28169, U.S.N.M. 



