520 ^^" Stephensen. 



tory part has not a small, separate, anterior part, as is usually the 

 case, but this is perhaps an abnormality in the specimen figured. 

 The palp is large, two-jointed. The hindmost part of the exopodite 

 is almost as long as the front part. 



The 1st pair of ma?^illipedes (fig. 16) resemble those of stage A 

 (fig. 6), but there are more setæ on the basal lobe and at the 

 base of the exopodite; the palp is smaller and has only a constric- 

 tion, not distinct joints. 



On the other hand, the 2nd pair of maxillipedes (fig. 17) differ 

 to a greater extent from stage A (fig. 7). The 2nd joint of the stalk 

 is almost twice as long as broad and the bend in the palp takes 

 place not at the 4th but at the 3rd joint. The exopodite is long 

 and thin and has 5 ciliated setæ. 



The 3rd pair of maxillipedes (fig. 18) are quite similar to stage 

 A (fig. 8), except that there is no exopodite and the stalk seems to 

 consist of onl}^ one joint. 



Of the pereiopoda (fig. 18) the 1st and 4th pairs (3rd and 5th 

 pairs wanting) greatly resemble the corresponding pereiopoda in stage A 

 (fig. 8), though the length of each of the joints is a little different. 

 In the 2nd pair however we find a difTerent condition, the right and 

 left legs not being the same. In form the right leg resembles that 

 of the adult Spirontocaris, the 5th joint however being only divided 

 into 4 rings; but the left leg is almost twice as long and has this 

 joint divided into 5 rings. 



Of the pleopoda the 1st — 5th pairs (fig. 19) also have the same 

 form as in the previously described stage (fig. 9), but the 6th pair 

 (fig. 20) is just as long as the telson. The stem-joint has a small 

 tooth on the outer side. The exopodite has almost parallel sides 

 but is a little narrower at the base and is roundedly pointed at the 

 tip; on the outer corner there is a small tooth, from which a 

 furrow runs in some distance on the plate. The whole of the outer 

 margin in from the tooth is densely beset with short, fine setæ. 

 The length is almost 5 times the greatest breadth. The endopodite 

 is elongated, lancet-shaped, broadest at the proximal l/5th. 



Regarding the development of Spirontocaris we have hitherto known 

 nothing, it is true, except the embryo of Sp. polaris (see above p. 515) 

 and a Mysis stage which was referred by Claus to this genus (Claus : 

 Zur Kenntnisse d. Malacostracenlarven, Würzburger naturwiss. 

 Zeitschr., vol. 2, 1861, p. 40, PI. 3, fig. 8); but the form of the 3rd 

 pair of maxillipedes and the pereiopoda permit of no doubt. Only 

 the 2nd pair of pereiopoda, with the great difference in length 

 between the right and left legs, remind one of the genus Pandalus, 

 but this character, at least provisionally, must be taken as an ab- 

 normality. The present specimen is older than the stage A. 



