NO. 2182. NEW SPECIES OF CRETACEOUS CRABS— RATHBUN. 389 



RelationsUps.— This species has considerable resemblance to H. 

 edwardsii ^ Bell, the type-species of the genus, but in the latter, the 

 protogastric lobes are each partially separated from the metagastric 

 lobes by a deep, transversely oblique furrow, the cardiac region bears 

 a small tubercle at its middle, the surface is everywhere granulated. 



H. depressa Carter,^ from the same localities as edwardsii, is also 

 granulated throughout and lacks the large areolar tubercles of punctata. 



Our species is near H. transiens Segerberg ^ from the Cretaceous of 

 Denmark, which however, has no large mesogastric tubercles, and has 

 three instead of four tubercles on each protogastric lobe. 



H. richardsoniWoodwsird,* from the Cretaceous of British Columbia, 

 and H. japonica Yokoyama,^ from the early Tertiary of Japan, have 

 a carapace much narrower anteriorly than those above mentioned. 

 They should probably be referred to a distinct genus. 



Subtribe OXYSTOMATA. 



? Family CALAPPIDAE. 



Genus CAMPYLOSTOMA Bell. 



Campylostoma Bell, Mono. Foss. Malac. Crust. Gr. Britain, pt. 1, 1857, p. 23. 



CAMPYLOSTOMA PIERRENSE, new species. 



Plate 33, figs. 4-5. 



Type-locality.— South Dakota: Eastern, Corson County; Pierre 

 Shale; Upper Cretaceous; July, 1915; W. H. Over; two specimens, 

 holotype and paratype, presented by the University of South Dakota, 

 Vermilion, South Dakota. 



Holotype.— Cat. No. 32057, U.S.N.M. 



Descriptionof holotype.— An incomplete carapace, showing dorsal 

 surface and an indication of the extent of one orbit. The orbit has a 

 somewhat dorsal inclination, is slightly acutangled externally and 

 has a tooth on the upper margin. The outer surface of shell, where 

 it persists, is finely granulate. Spines conical. Five spines in a 

 transverse row on the gastric region, which arches upwards toward 

 the middle; row not quite straight, but slightly concave forward; 

 distance from the middle spine to those of the submedian pair less 

 than from the latter to those of outer pair. A median ridge runs 

 back to the hinder border of the cardiac region, and bears five spines, 



1 Mono. Foss. Malac. Crust. Gr. Britain, pt. 2, 1862, p. 23, pi. 5, flgs. 1 and 2. From the Gault at Foikes- 

 stone and the Greensand at Cambridge. 



2 Quart. Journ. Geol. Soc. London, vol. 54, 1898, p. 22, pi. 1, fig. 5. 



3 Geol. Foren. i Stockholm Forhandl., vol. 22, 1900, Hiifte 5, p. 366, pi. 8, flgs. 6-8. AlbO, Woodward, Geol. 

 Mag., London, new ser., dec. 4, vol. 8, 1901, p. 499. 



< Quart. Journ. Geol. Soc. London, vol. 52, 1896, p. 224, text-fig. 3. 



6 Journ. Coll. Sci. Imper. Univ. Tokyo, vol. 27, 1911, art. 20, p. 12, pi. 3, fig. 4. 



