REPORT ON THE STOMATOPODA. 97 



and there are few (five or six) marginal spines on the outer edge of its oxopoditc. In 

 the older larv« the dactylus of the raptorial limb shows traces of six spines besides the 

 marginal one. 



In the youngest Alimerichthus which has been observed (PI. VIII. fig. 8) the 

 flagellum of the second antenna is represented by a bud, as are also the appendages of 

 the third thoracic somite, and the third, fourth, and fifth thoracic somites are cro°wded 

 together so that the sum of their lengths is about equal to the length of each one of the 

 three last thoracic somites, upon which there are no traces of appendages. There are five 

 pairs of fully developed and functional abdominal appendages, and five distinct abdominal 

 somites, the first four wider than the thorax, but the fifth very narrow and deeply con- 

 stricted off from the telson, upon the anterior edge of which the sixth pair of abdominal 

 appendages are represented by buds. The telson is wider than long, and nearly four 

 times as wide as the abdomen. It has six pairs of marginal spines with numerous 

 minute secondary spines between the submedians, ten or eleven on each side between the 

 submedian and adjacent intermediate, and a single one internal to the base of the lateral. 

 The margin of the telson, between the submedian and the intermediate, makes an angle 

 of about 45° with the principal axis of the body. A comparison of this larva with tlie 

 corresponding stage of Alima gracilis (PI. IV. fig. 5), or of Alima macrophthcdma 

 (PL VIII. fig. 1), shows that there is every reason for believing that it is preceded 

 by an earlier stage like the youngest observed stage of Alima yracilis (PL IV. fig. 4), 

 of Alima macrophthalma (PL VII. fig. 2), or Alima {Squilla) empusa (PL I. fia 4),' 

 and that at this time the third, fourth, and fifth thoracic somites are long and without 

 appendages like the. sixth, seventh, and eighth; the fifth abdominal somite and its 

 appendages absent or rudimentary, the sixth absent, and the telson spatulate, with the 

 submedians wide apart, and the secondary dentations between the submedians and inter- 

 mediates about as large as the primary spines. As we know that some, and probably 

 all, of the Alimxi larvae hatch from the egg in this condition, and do not pass through a 

 free Erichthoidina stage, this is undoubtedly true of the Alimerichthus also. 



In the next stage which has been observed (PL IX. fig. 3) the appendages and 

 somites are all present, the exopodites of the first five abdominal appendages carry at 

 their bases the rudimentary buds which are to become the giUs, the telson is shorter 

 and wider than before, and the intermediate marginal spines have travelled backwards 

 until the posterior margin of the telson is nearly transverse between them. The sixth 

 abdominal appendages are still small, but in the next stage, the one shown in Claus's 

 fig. 30, they are nearly as long as the telson, with six or seven marginal spines on the 

 outer edge of the exopodite and with the inner spine longer than the outer, with an 

 obscure lobe on its outer margin near the base. The whole hind body is now wide and 

 flat, and there are indications of five or six marginal spines on the inner edge of the 

 dactylus of the raptorial claw. 



(ZOOL. CHALL. E.\r.— PART XLV. — ItjSG.) y,, jg 



