Studies on marine Ostracods 251 



and has short liairs. The o x o p o d i t e (fig. 9) has about the following proportions 

 between its joints: 



I : II : III : IV : V : VI : VII : VIII : IX = 55 : 11 : 6 : 5 : 5 : 5 : 5 : 5 : 3. 

 In other words the first joint is somewhat longer than all the other joints together, the second 

 joint has about the total length of the third and fourth joints. The bristle of the second joint 

 is about as long as the five to seven following joints and is furnished with from about nine 

 to thirteen powerful ventral secondary teeth. The proportion between the longest natatory 

 bristles and the total length of the exopodite is about 13 : 10. These bristles have broad 

 natatory hairs (about the same as in C. (Macrocijpridina) castanea; see fig. 12 of this species). 

 The end joint has four bristles, of which the dorsal one is quite short, attaining about the total 

 length of the three or four distal joints, with short, fine hairs or almost naked. The third to 

 the ninth joints have strong and rather long conical basal spines, the proximal ones somewhat 

 shorter than the distal ones, the one on the third joint being specially short iu comparison with 

 the others. At the base of the bristle of the second joint there is a series of short and moderately 

 strong spines. Endopodite (fig. 10, (J = $): This is comparatively well developed, 

 elongated and triple-jointed. Its first joint has proximally a group of four bare or almost 

 bare bristles, three of which are subequal, rather short, scarcely attaining half the length of 

 the fourth; the latter is about the same length as the second or the second and third joints. 

 Somewhat distally of this group there is a single bristle with short hairs, which is generally 

 somewhat longer than the longest of the four bristles mentioned. The second joint has distally 

 a single bristle, with short hairs or almost naked, which is somewhat longer than the end joint. 

 The bristle of the end joint is about twice as long as the endopodite. 



Mandible (fig. 11): — Protopodite: The endite on the coxale has very 

 numerous spines; it is weakly bifurcated, the two distal points are considerably stronger than 

 the other spines of the process; between the two distal points, which, unlike the other spines, 

 are furnished with a few weak secondary teeth, there is a low, powerful wart. Basale: This 

 has seven bristles ventrallv: two a-bristles, one b-bristle, two c-bristles and two d-bristles. 

 The a-bristles are soxuewhat different in length from each other, the longest one being about 

 as long as half the height of the joint; the b-bristle is short; one c-bristle varies somewhat in 

 length and is about as long as the height of the joint, the other is short; the shortest d-bristle 

 is somewhat shorter than the longest c-bristle, the longest d-bristle is about as long as the 

 endopodite. Of the three dorsal bristles on this joint the proximal one is fixed somewhat in 

 front of the middle of the joint and is about half its length; of the two distal bristles one is about 

 as long as the proximal dorsal bristle, the other about double its length; all three have short 

 hairs. Exopodite: This is about as long as the dorsal side of the first endopodite joint 

 or somewhat longer. Of its two bristles, both furnished with short hairs, one is about as long 

 as the exopodite, the other is somewhat longer. Endopodite: The longest of the four 

 ventral bristles on the first joint has some irregular wreaths of long, stiff secondary bristles and 

 has short hairs distally, the others have short hairs. Second joint: On the anterior side there 

 are from eleven to fourteen more or less long bristles with short, fine hairs; the longest of those 

 that are fixed distally reach the end joint with their points. There are, in addition, from 



