122 DE. J. D. F. GILCHRIST ON LARVAL AND 



branch, separating it still more effectively from the second. Ultimately the 

 calcification extends completely round the first and over the pleura generally, 

 and the anterior pleurobranch is still higher up the side. 



The puerulus here described does not quite agree with that described by 

 Bouvier (2) from the island of St. Paul, and suggested by him to be that of 

 Jasus lalandii. Thus, there is no very distinct dorso-lateral ridge, and there 

 are fewer spines on the dorsal region of the carapace ; the exopodite of the 

 third maxillipede does not nearly reach the articulation of the ischiopodite 

 with the raeropodite as in his specimens. The frontal spines are, however, 

 slightly convergent, and it may represent an earlier stage than that described 

 by Bouvier. Grruvel (4) also describes some young forms of this species 

 from the island of St. Paul, but not in sufficient detail for a comparison with 

 our specimens. 



Review of Results. 



The larvse of the first and second stages of Jasus lalandii can readily be 

 hatched out from the egg. Larv^ of the second stage were found in 

 abundance in the inshore waters during the summer months, and a much 

 smaller number of more advanced stages (up to 37 mm. in length) in deep 

 waters. The puerulus stage can be found close inshore. These were all 

 found on the west coast of S. Africa, and are regarded as stages of Jasus 

 lalandii, the only known representative of the Scyllaridea in this region, 

 where it occurs abundantly. 



Three other kinds of phyllosoma and two kinds of puerulus occur on the 

 south and east coasts, apparently belonging to other South-African Scyllaridea 

 {Palinurus, RanuUrus, and Scyllarides). 



The appendages of the first or naupliosoma-stage are described and figured. 

 The second or phyllosoma-stage (1'7 mm.) differs from it in the absence of 

 the swimming setce of the antennas, the appearance of the flagellum of the 

 endopodite, the presence of olfactory (?) filaments on the antennules, etc. A 

 phyllosoma of 3*8 mm. shows relative increase in size of shield, decrease in 

 length of walking-legs, diminution of the exopodite of the antenna, absence 

 of first maxillipede, appearance of the fourth walking-legs, etc. A phyllo- 

 soma of 24 mm. shows still greater relative increase in size of shield, flagella 

 appear on antennules, antennse are three-jointed and their exopodites have 

 disappeared, the distal part of the maxilla has broadened out and expanded 

 posteriorly to form the scaphognathite, the first maxillipede reappears as a 

 simple stump with two slight projections, and pleopods appear as simple 

 biramose organs. A phyllosoma of 26 mm. shows no essential change, but 

 in one of 33 mm. the gill-rudiments appear and a rostral elevation with 

 three prominences, the middle one of which may represent the rostrum, the 

 other two the ocular spines. The mandible consists of three strong spines, 

 followed by a series of small spines, inserted on an elongate edge and 



