CALIFORNIA CUMACEA ZIMMER 433 



no. 1 a ridge or keel (keel no. 1) runs obliquely forward and 

 terminates about at that point where the pseudorostral margin, in 

 forming the subrostral notch, curves downward; another ridge 

 (keel no. 2) runs obliquely outward and forward in a flat ante- 

 riorly open curve onto the ventral margin of the carapace, which it 

 strikes a little distance behind the subrostral angle. Keel no. 3 

 runs obliquely backward and upward and forms a connecting ridge 

 or keel between angles nos. 1 and 2. Running out from this angle 

 no. 2 are also the following ridges or keels : Keel no. 4 at first runs 

 posteriorly and then, bending outward and forward, in the latter 

 part of its course runs practically parallel to the lower margin 

 of the carapace but at a little distance removed from it; finally it 

 runs up against keel no. 2 and ends at that point. Keel no. 5, 

 forming a very flat, anteriorly open curve, extends nearly per- 

 pendicularly to the median line; it does not, however, meet its 

 counterpart on the opposite side of the carapace, as a narrow gap 

 or interval intervenes between the two. At this point, within the 

 gap, the surface of the carapace is deeply impressed; this impres- 

 sion is briefly continued backward. In lateral view the dorsal 

 contour of the carapace in advance of keel no. 5 suddenly slopes 

 steeply, yet evenly, downward to the pseudorostrum. 



The telson (fig. 37, c) is as long as the last abdominal somite, 

 or the equally long penultimate one. In the preanal portion of the 

 telson the lateral margins converge but slightly; on the other hand^ 

 the postanal portion, which is a little more than half as long as the 

 preanal, narrows abruptly. On each side of the postanal portion 

 of the telson there are about four lateral spines in addition to the 

 terminal pair. 



The antennule (fig. 37, d) is slender and exceeds the pseudo- 

 rostrum by the last joint of its peduncle. 



The basis of the third maxilliped (fig. 37, e) distally is markedly- 

 broadened and, moreover, its outermost portion is not inconsiderably 

 produced; its outer margin is dorsally turned upward a little. At 

 the "mouth-field" is considerably narrower than the combined basej 

 of the two maxillipeds, these at their line of contact form a roof, tha 

 angle of whose ridge is higher than normal. As a consequence, mor;j 

 of the third maxillipeds is to be seen in lateral view (fig. 37, a) in 

 this species than is usually the case. Not one of the specimens pos- 

 sessed a complete first pereiopod. One female, however, had a first 

 pereiopod complete on the inner side except for a portion of tho 

 dactylus. The distal extremity of this particular limb is long and 

 slender ; carpus less than half as long as the basis ; propodus clearly 

 longer than the carpus. The second pereiopod also is slender; last 



