NO. 3 COPEPODA FROM PANAMA MARSH 15 



segments and one-half the third. The second, third, and fourth seg- 

 ments are about equal in length. 



The furcal rami (pi. 4, fig. 6) somewhat exceed in length the last 

 cephalothoracic segment. The lateral setae are situated at the distal 

 third. The longer of the terminal setae is nearly as long as the 

 abdomen and furca. 



The first antennae (pi. 4, fig. 8) are short and composed of twelve 

 segments. 



The inner margin of the claw of the maxillipede is armed with five 

 prominent teeth. These are shown in plate 4, fig. 9, and more clearly 

 in the figure of the claw (pi. 4, fig. 12). The presence of these teeth 

 is a unique feature and the specific name is given because of this 

 structure. 



The rami of the swimming feet are two-segmented. The spinous 

 armature of the terminal segments of the exopodites is represented 

 by the formula, 3, 4, 4, 3. Plate 4, fig. 7, shows the fourth foot, and 

 plate 4, fig. 5, the terminal segment of the endopodite of the first foot. 

 The connecting membrane between the fourth feet is armed with two 

 rows of fine spines. 



The fifth feet (pi. 4, fig. 11) are one-segmented. This segment 

 is elongated, its length being about three times its width. It is armed 

 at the distal end with a minute spine and a seta, which is a little more 

 than twice as long as the segment. 



Cyclops dcntatimamis was found on the savannas between Panama 

 and Old Panama in a stagnant stream in which were large numbers 

 of C. ceqiioreus and C. panamensis. In the collection a glance was 

 sufficient to show its specific distinction from C. panamensis because 

 of its larger size and short antennae. Only a few individuals were 

 found of this species. Two of them were mature females. As they 

 were dissected before measurements were taken, on the assumption 

 that a larger number would be found, the description is incomplete 

 as far as the morphology of the cephalothorax is concerned. The 

 species, in its general structure is almost identical with Cyclops 

 anccps Richard (Richard, 1897), which was found in Brazil. The 

 receptaculum seminis, however, is of a different form, and Richard 

 does not mention the peculiar structure of the maxillipede, which 

 was so noticeable in C. dentatimanus. It is highly improbable that 

 such a structure would have escaped the notice of so skilled and 

 experienced an investigator as Richard. Daday (Daday, 1902b, 443), 

 who afterwards identified C. anccps in material from Chili, does 

 not mention any unusual form of the maxillipede. Later he records 



