254 G. M. Giles — Notes on the Amphipoda of Indian Waters. [No. 3, 



stout, forwardly directed, dorsal spines, one situated about the middle of 

 the segment, and the other at its hinder edge. 



3rd. There is more difference between the antennae, the superior 

 pair being proportionally larger. 



4th. The 2nd thoracic appendage has its propodite better de- 

 veloped. 



5th. The 3rd thoracic appendage is somewhat smaller. 



EXPLANATION OF THE PLATES. 

 Plate VI. 

 Fig. 1. Anonyx amaurus, x 12. The dotted line beneath the body shews the 

 outline of the brood-pouch. The coxal plates are represented as semitransparent, in 

 order to shew the form of the parts beneath ; they are in point of fact, however, 

 quite opaque. Fig. 2. Elsia indica, ? , x 24. Fig. 3. Antennule, x 100. Fig. 4. 

 One of the gnathopods, x 100. 



Plate VII. 



Fig. 1. Microdeutopus megnce, cf , x 11. Fig. 2. Gnathopoda of female, x 11, 

 Fig. 3. Mandible and its appendage, x 40. Fig. 4. Pediform ramus of the maxil- 

 liped, to shew its relative proportions to the mandibular palp, x 40. Fig. 5. 

 (Edicerus puliciformis, x 19. Fig. 6. Terminal joints of gnathopoda, x 50. 

 Fig. 7. Concholestes dentalii, x 10. Fig. 8. Head, seen from above, x 10. 

 Fig. 9. Subchela of 2nd gnathopod, x 50. Fig. 10. Distal joints of 6th thoracic 

 appendage, x 50. Fig. 11. Last three abdominal segments, x 40. Fig. 12. 

 Monoculodes megapleon, x 12. 



Plate VIII. 



Fig. 1. Ampelisca lepta^ x 20. Fig. 2. Last three abdominal segments and 

 appendages, x 40. Fig. 3. The mandible and its appendages, x 40. Fig. 4. 

 Sifting plate of mandible, x 200. Fig. 5. Cutting plate of mandible, x 200. 

 Fig. 6. Ist maxilla, x 40. Fig. 7. 2nd maxilla and maxilliped, x 40. Fig. 8. 

 One of the rami of 2nd maxilla, x 100. Fig. 9. Imperfect subchela of 2nd 

 thoracic appendage, x 100. Fig. 10. Ramus of one of posterior abdominal appen- 

 dages, X 100. 



Plate IX. 



Fig. 1. Transverse section of head ( x 100) of A. lepta at the level of the 

 upper pair of eyes; (a) chitinous coat of animal, (6) lens, (c) lens of the other 

 side dislocated and shrunken with contained fluid oozing out, (d) epithelial layer 

 of dermis deeply pigmented to form a sort of iris, (e) retina. Fig. 2. A portion 

 of retina of preceding, x 600 ; (a) deepest layer of spindle-shaped bodies, 

 (h) middle layer of nucleated rods divided below into fibres inosculating with 

 ends of the preceding layer, (c) deeply pigmented rods external to middle 

 layer, (d) epithelial layer of dermis. Fig. 3. Vertical longitudinal section of 

 head of A lepta x 100, cut a little to one side of the middle line in the plane 

 of the inner pair of eyes ; (a) inner eye, (b) cerebral nervous mass (the upper 



