NATURAL SCIENCES OF PHILADELPHIA. 335 



CEEATIOCARIS (SOLENOCARIS) STRIGATA, Meek. 



Carapace-valves narrow, and elongated, rather convex, with 

 length about four times the height ; dorsal and ventral margins 

 nearly straight and parallel, anterior extremity very narrowly 

 rounded, being most prominent at the middle; posterior end very 

 obliquely truncated from below backward and upward so as to 

 impart a more or less angular or pointed character to the poste- 

 rior dorsal extremity, which, however, is not curved. Surface of 

 internal cast showing rather well-defined mai'ks of growth parallel 

 to the margins ; while moulds of the exterior show impressions 

 of coarse, more or less anastomosing, longitudinal strise, that do 

 not curve exactly parallel to the free margins, particularly of the 

 ends. jSTo ocular spot or tubercle visible. 



Length, 1.24 inch; height, about 0.30 inch; convexity, about 

 0.25 inch. 



I did not submit this form to Professor Dana, but as it differs 

 quite as materially (though in other respects) from Ceratiocaris 

 as those I sent to him do, and as widely, or even more widely, 

 from those I sent than the latter do from Ceratiocaris proper, I 

 have ventured to suggest for it at least a subgeneric name, Soleno- 

 caris. It shows no traces of ocular spots, and merely has the 

 posterior end subtruncated obliquely backward from below, with- 

 out any traces of a sinus. At a first glance, it looks like the 

 valves of a narrow bivalve mollusk ; but its sculpturing is de- 

 cidedly of crustacean type, being like that of some species of Cera- 

 tiocaris. 



Locality and position Same as preceding. 



ARCH.ffiOCARIS VERMIFORMIS, Meek. 



The specimens of this fossil j^et known are too imperfect to be 

 systematically characterized, but they may be described, in a 

 gene^-al way, as follows; the description being intended to apply 

 to a side view of individuals as seen more or less compressed 

 laterally in concretions. 



Cephalothorax or head, about equalling the length of the first 

 three and a half of the bod}^ segments behind it ; subtrigonal in 

 form, being somewhat pointed in front, with the posterior margin 

 wider and obliquely truncated from above backward and down- 

 ward, so as to give more or less angularity to the posterior basal 

 extremity ; basal margin apparently with a kind of ridge or fold 

 1872.] 



