MORPHOLOGICAL NOTES. 



of the animal, and that we thus may find them increasing or decreasing 

 in volume according to the stage of the development of the ovaria. 



The other glands present within the joints of the legs have pro- 

 bably a different function, according to the place they occupy, and so I 

 am inclined to think that the highly developed glands in the uropoda 

 and telson of Xiphocephalus are poison-glands. 



13. The young. 



The eggs are in the family Oxycephalidae packed in, and pro- 

 tected by a pouch formed of five pairs of ovitectrices, attached to the 

 second and four following pairs of peraeopoda. There the eggs rest until 

 the time of hatching, when the young have a form very similar to that 

 of a true Hyperia. 



In the Xiphocephalidse also 

 the young remind one of the form 

 occurring in Hyperia, Vibilia, and 

 other genera of the first two subtribes. 

 But the manner of bearing the eggs 

 is a very peculiar feature. No ovitec- 

 trices exist but the eggs are placed 

 under the perseonal segments, between 

 the lower parts of the sides where 

 they are fixed in two regular rows, as mentioned above (p. 31). When 

 the young are ready to be hatched we find that each egg is cemented 

 to the under surface of the peraeon with the head-end, and that the 

 young hang tail downwards (fig. 48 and 49). 



The first pair of antenna in the just hatched young one of Xi- 

 phocephalus consist of two small tubercles fixed at the anterior side 

 of the head, and no trace of a rostrum is to be seen. The first and 

 five following pairs of peraeopoda are developed, all simple and sub- 

 similar in form, and armed with strong claws, the first and second pairs 

 subequal in length, and more than half as long as the following pairs. 

 No trace of the seventh pair is to seen. The pleon and urus are com- 

 paratively short, much shorter together than the perseon. The pleopoda 

 are represented by egg-shaped vesicles. The second and third ural seg- 

 ments are free, not coalesced, each carrying a pair of small vesicles, the 

 uropods (fig. 86). 



fig. 86. A. young, just hatched, of 

 Xiphocephalus Whitei. 



