THE FOSSIL STALK-EYED CRUSTACEA 137 



on left bank, four-tenths mile north of Granp:ers Hall, Sonoma 

 County: Pliocene (?) series; one specimen, holotype, extending from 

 the hind part of the thorax to tlie sixth abdominal segment, inclusive. 

 Holotype in University of California. 



Relations. — As the holotype lacks those parts commonly used in 

 diagnosing species, namely, the anterior and posterior ends of the 

 body and all of the appendages, it is impossible to assign the fossil 

 species to its proper place within the genus. It appears to be related 

 to certain of those species which now inhabit the deeper waters off 

 I he Pacific coast of North America: C. panamensis (Bigelow)" and 

 C. hiforrtvk (Bigelow).*'^ The carapace is similarly carinated, espe- 

 cially that of panmnensis, where the space between the branches of 

 the median carina behind the transverse suture is the same form and 

 I he space outside the intermediate carina is equally oblique, but in 

 sonomana the space is considerably wider in proportion to the full 

 width of the carapace, and the posterior curve of the carina is a 

 wider arch. The lateral carina of the sixth abdominal segment is 

 similar in direction in the three species, and is interrupted in the 

 middle, but neither of the Recent species has the same blunt tooth 

 behind the break as is seen in sonomana. 



Genus PSEUDOSQUILLA Guerin MS., Dana 



PKCKdosqiiilla Guerin, in Dana, U. S. Expl. Exped., vol. 1.3, Crustacea, 

 pt. 1. 1852, pp. 615 and 621; type, P. lessonii (Guerin). 



Carapace without carinae. Cervical groove not extending across 

 (lor.sum of carapace. Cornea of eyes rarely bilobed. First five ab- 

 dominal somites without longitudinal carinae. Abdomen usually 

 compressed. Raptorial dactylus not inflated at base and with two, 

 rarely three, teeth (excluding terminal tooth) on inner margin, or 

 nnarme 1. Telson with sharp median carina and in adults with other 

 carinae on either side, the submedian with movable tips; no marginal 

 submedian denticles, never more than three intermediate denticles. 



Pliocene: Recent. 



PSEUDOSQUILLA ADELAIDENSIS, new species 



Plate 38, fig. 3 



DescHption. — The species has the strongly arched abdomen with 

 the first five segments smooth which characterizes all the members 

 of the genus. The sixth segment shows four carinae, .submedian, 



" Proc. U. S. Mus., vol. 17, 1894. p. 526, text-figs. 17 and 18. 

 «^Idem, p. 532, pi. 21, text-fig. 20. 



