THE FOSSIL STALK-EYED CRUSTACEA 85 



The mesogastric region anteriorly narrows gradually not suddenly. 

 There are 15 dorsal tubercles (pi. 18, fig. 1) : one on each proto- 

 gastric region; two mesogastric, the posterior one large and high, 

 the anterior one low ; the cardiac elevation large and low ; two epi- 

 branchial tubercles placed obliquely not far apart ; one metabranchial 

 at the end of a blunt ridge which runs obliquely forward and out- 

 ward from the postero-lateral angle of the carapace; one small 

 hepatic tubercle; one small low tubercle in the depression at the 

 inner angle of the branchial region. The lateral margin is thick 

 and unmarked by a raised or granulated line (pi. 18, fig. 2). There 

 are three lateral spines or teeth behind the orbit ; all are broken off 

 except the left one of the pair situated a little behind the middle of 

 the carapace; it is short, conical, blunt; the distance between it and 

 the second spine is nearly twice that between the first and second. 

 The orbital margins are broken away but there is indication of a 

 forw ard-pointing spine at the outer angle and another near the mid- 

 dle of the upper margin; farther inward are the bases of two other 

 spines or teeth and below the outer of these two projects at some 

 distance the spine at the inner angle of the lower margin of the 

 orbit {lo, fig. 1, pi. 18). 



Measurements. — Greatest Avidth of carapace exclusive of spines 21 

 mm., posterior Avidth 10.7 nmi., wddth across front and orbits 14.2 

 mm., length from one of the submedian spines of the frontal margin 

 to the posterior margin 19.3 mm. 



Occurrence. — California : 1 mile southeast of Oil City, Fresno 

 County; Eocene series (Tejon of Arnold) ; one specimen of carapace 

 with anterior margin lacking; holotype in California Academy of 

 Sciences. 



Relation. — This species seems to fit into Necrocarcinus better than 

 into any other fossil genus; it has a similar shape of carapace, of 

 mesogastric region, possesses lateral spines and a few dorsal tu- 

 bercles. On the other hand, the gastric region as a whole is wider 

 than those figured by Bell for his three species of Necrocarcinus 

 and suggests rather the genus Orithyia ^^ ; the arrangement of the 

 orbital spines as I see it is similar to that in OHthyia., but the shape 

 and lateral spination is quite different. 



Subtribe Dromiacea de Haan 

 Superfamily HOMOLIDEA Alcock 

 Family HOMOLIDAE Henderson 



r 



Carapace longer than broad, more or less quadrilateral, ovoid, or 

 urn-shaped; lineae anomuricae (a pair of longitudinal suture lines 



^ Weber, Xomenclator eiitom'ologicus, 1795, p. 9'3 ; type, O. »inicus (Linnaeus). 



