PLATE VIII. 



The Roman numerals denote the appendages of the body in their consecutive order 



1-4. Development of Stomatopoda, conthuieJ. Figures from W. K. Brooks and 



Walter Faxon. 



1. Larva of Squif!a empusa, older than the one represented on Plate VII. fig. 19. Ventral view. The anten- 



nulary segment has become marked off at the anterior end of the body, and the third fl.agellum of the adult 

 antennule is present. The second antenna has a rudimentary three-jointed inner branch or flagellura. The 

 si.x posterior thoracic appendages have acquired essentially their permanent form. The sixth abdominal 

 somite has become free and bears a pair of large swimmerets (XIX) similar in form to those of the adult. 

 The abdominal appendages of the left side are omitted in the figure. From Brooks, Ibid., PI. XI. 



2. Still older stage of the same, dorsal view. Length 17 mm. The abdominal appendages are not shown in the 



figure, e.xcepting the last pair (XIX). From a sketch by Faxon, made at Newport, R. 1., August 24, 1876. 



3. The specimen represented in fig. 2, moulted on the 25tli of August, assuming the form shown in fig. 3, 



from the lower side. It is now 19 mm. long, and has the characters of the adult Squilla empusa. All 

 the abdominal limbs are present, but are omitted in the figure with the e-'cception of the last pair (XIX) and 

 the light one of the first pair. From a sketch by Faxon. 



4. Part of the border of the telson of the same, more highly magnified. 



5 - 8. Develojment of Cumacea. Fignre.s from Anton Dohrn, Uutersuclmngen viber Ban 

 mid Eutwickeluiig der Artliropodeii. 1. Ueber den Ban mid die Eutwickeluiig der 

 Ciimaceeu. Jenaische Zeitschr., V., Taf. II., 1870. 



5. Early stage in the development of the embryo of Cuma Goodsiri. a, contour of the body, ft larval skin. 



7, chorion. K, dorsal organ. Behind the dorsal organ a deep fold gives the embryo a marked dorsal 

 flexure. Through this dorsal flexure and dorsal organ the embryo e.x:hihits a striking resemblance to the 

 embryo of Isopods. Of. Plate VI. The sixth pair of appendages, however, uidike the corresponding pair 

 in the Isopod embryo, at this early stage is two-lobed and resembles the six following pairs of appendages. 

 Eudiments of all the append.ages are present from the first to the twelfth, c p, carapace conimcncing as a 

 fold in the region of the maxillie. /, liver. 



6. Later stage of the same. The outer membrane has been cast off'. The caudal appendages (XIX) are present. 



7. Later stage. The embryo now approaches the Decapod type. The larval skin has been shed, the dorsal organ 



has disappeared, and the dorsal flexure is exchanged for a ventral one. The bulk of the first niaxilliped (VI) 

 is formed from the exopodite while the .similar second niaxilliped (VII) represents the endopodite alone, 

 the external branch having entirely disappeared. X', Xl', rudimentary exopodites of the tenth and eleventh 

 pairs of appendages. The twelfth pair is now devoid of external branch. 



8. Lai-va ready to leave the brood-sac. c, place of attachment of the branchial apparatus. The last pair of 



thoracic legs has not yet developed, nor the appendages of the abdomen except the last pair (XIX). The 

 abdominal appendages are never developed in the female. The eyes, which are not shown in the figures, 

 are developed on each side of the head, and coalesce at a later period to form the median sessile eye of the 

 adult. 



