studies oil marine Ostracods 305 



The bristles of the third and fourth joints and the middle one of the three bristles on the end 

 joint are, in addition, furnished, the two former ventrally, the latter dorsally, with a series 

 of very coarse, strong, smooth spines, somewhat blunted and rounded distally (the species has 

 obtained its name from this character); the number of spines on each bristle seems to vary, 

 from twelve to eighteen have been observed; they are so placed that when the natatory bristles 

 are situated closely along each other a single row of spines is formed, in other words, the spines 

 on the bristle of the fourth joint are situated so as to form a direct continuation of those of the 

 preceding bristle and the spines on the bristle of the end joint are a continuation of those of 

 the bristle on the fourtli joint; the row of spines on the bristle of the third joint begins a rather 

 long distance from the base of the bristle, the unarmed proximal part of this bristle corresponding 

 in length to about the total length of the five or six distal joints. (This unarmed part is protected 

 by the strong bristle of the second joint). The end joint has only three bristles, of which the 

 two ventral ones are developed in the same proportions as the natatory bristles of the 

 preceding joints; the dorsal one, which also has long, well-developed natatory hairs, situated 

 close together, is about as long as the total length of the eight distal joints. The four distal 

 joints have powerful basal spines; the basal spines on the third to the fifth joints are, on the 

 other hand, very small, especially those on the third and fourth joints, which can only be observed 

 with difficulty. Endopoditc (fig. 10): This is short and verruciform, with only an indication of 

 having two joints. Proximally it has three bristles of somewhat different lengths, the longest 

 being comparatively long, more than double the length of the shortest and about as long as the 

 total length of the four distal exopodite joints; they all have short hairs or are almost naked. 

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

 moderate number of spines. It is — as has been pointed out above — weakly bifurcated 

 distally, the two distal points are considerably stronger than the spines and are almost quite 

 bare; between these two points there is a verruciform process. The basale has seven bristles 

 ventrally: three a-bristles, one b-bristle, two c-bristles and one d-bristle. Of these the a-, b- 

 and c-bristles are short, the b-bristle being even rather difficult to distinguish, the d-bristle 

 is about as long as the second endopodite joint. At the base of this last bristle there is no short 

 bristle, contrarv to what is the case in all the other species of this sub-family that are dealt 

 with in this work. Of the three bristles on the dorsal side the proximal one is fixed at or just 

 behind the middle of the joint and is quite short, being only about a fifth to a quarter of the 

 length of the dorsal side of this joint; the two distal bristles are similarly rather short, one being 

 about as long as the dorsal side of the first endopodite joint, the other twice as long; all these 

 three bristles have short hairs. The e x o p o d i t e is a good deal shorter than the dorsal side 

 of the first endopodite joint; both its two bristles have short hairs or are almost bare; the longest, 

 the proximal one, is about as long as the longest distal bristle situated dorsally on the second 

 protopodite joint, the distal one is short, about as long as the exopodite. Endopodite: 

 Of the four ventral bristles on the first joint the longest one, which is not quite as long as the 

 posterior side of the second endopodite joint, has numerous long secondary bristles arranged 

 in irregular wreaths, and has short hairs distally; the other three have short hairs. Second 

 joint: This has rather few bristles on the anterior sidn; these are concentrated on the proximal 



Zoolog. bidrus. Uppsala. Suppl.-lid. 1. •'•' 



