16 University of California Publications. [Zoology 



as in Covchoecia with three groups of respiratory filaments. Sec- 

 ond foot with two setae directed backward and upward. Fnrca 

 with six spines. 



1. Archiconchoecia striata Miiller. 



PI. Ill, figs. 1-3. 



1894. Archiconchoecia striata Miiller, G. W., p. 225, pi. VI, figs. 31-4G, 49, 

 and pi. VIII, fig. 34. 



Shell rather short and compressed, ratio of height to length 

 varying between 1:1.6 and 1:1.75; greatest height about two- 

 thirds of the way back; posterior to this point the ventral margin 

 bends upAvard rather strongly, but anteriorly it bends upward 

 more gradually. The posterior margin forms an arch whose 

 highest point lies about a third of the distance down from the 

 dorsal margin ; near this point, rather widely removed from the 

 posterior end of the dorsal margin, lie the openings of the glands, 

 almost but not quite symmetrical on the two halves of the shell. 

 Kostrum short, but distinct, pointed. Surface of the shell stri- 

 ated, the striae being especially distinct on the anterior half 

 where they run parallel to the dorsal and anterior margins; they 

 are connected bj^ anastomoses. About the middle of the ventral 

 margin, near the edge, is situated a circumscribed spot which is 

 not equally distinct in all individuals, but which is especially 

 distinct in stained shells. Frontal organ straight in both sexes, 

 with a blunt end which possesses a small process in the male ; in 

 the male longer, in the female shorter than the antennule. An- 

 tennule indistinctly jointed in both sexes, tolerably short, some- 

 what longer in the male than in the female; the six sensory 

 setae are of equal length, about one and a half times as long as 

 the antennule. Secondary branch of antenna with five sensory 

 filaments Avhich are almost equal in length and similar in shape ; 

 a few small papillae on lower part of first joint; the hook is 

 strong. Spines of the furca slender, the first longer and stronger 

 than the second. Upper lip with paired folds at its anterior edge 

 and a long gland which extends up to the base of the antennule. 

 Living animal yellowish, especialty in the anterior half and along 

 the ventral margin. 



