Quite well towards the head end a pair of buccal ganglia were found, these were small, widely separated and possessed only a few nerve cells. At about this level in cross sections the eyes make their appearance, one on each side. They are simple, quite large and well provided with pigment. Below the level of the eyes and the buccal ganglia, on the dorsal side of the esophagus, the much larger cerebral ganglia make their appearance. These probably are connected with the eyes but the connections were not clearly seen in the sections. The cerebral ganglia are closely united along the middle line. They occupy more than one half the diameter of the entire animal. The more caudal ends of these ganglia separate and run down, a little lateral to the esophagus. Below the esophagus and a little below the chief level of the cerebral ganglia, a region of more ventral masses of nerve tissue is reached. There are two ganglia on each side, a lateral pair somewhat smaller than the more ventral. The lateral are the pleural and the ventral are the pedal ganglia. The pedal ganglia are closely pressed against each other in the middle line, but not fused, they are much larger than any of the other ganglionic pairs and of a more complicated cell and fibrous structure. Beyond the region of large ganglia and slightly farther towards the other end of the animal, on the right side, a small visceral ganglion makes its appearance. Farther down on the left side a much smaller group of cells seems to indicate another ganglion of the viscera. [Illustration: Explanation of Figures] Fig. 1 Camera lucida sketch of cerebral ganglia of Cæcum. The dorsal side is up. ×300 Fig. 2. Left pleural ganglion of Cæcum. ×300. Fig. 3. Left pedal ganglion of Cæcum. ×300. Fig. 4. Reconstruction from Cæcum, showing position of eyes and ganglia viewed from the ventral side. ×70. Amphipods from Laguna Beach The following list is from the collections of 1917, or that part of it sent to the U. S. Nat. museum for determination. _Aruga oculata_ Holmes. L. 6 mm., white with red on the head. From algæ. Another white specimen of 8 mm. Dredged at 10 f. _Paraphoxus_ sp. L. 9 mm. Light colored. _Ipiplateia_ sp. Red. L. 10 mm. _Lilljeborgia brevicornis_ Bruz. One specimen dredged Aug. 28. Head white upper half, lower half pink. Lower part of body pink, upper white. L. 6 mm. Another head end of body red, caudal end white. L. 4 mm. Dredged Aug. 11 and Sept. 17th. _Tiron_ sp. Light colored. L. 9 mm. _Elasmopus brasiliensis_ Dana? L. 6 mm., yellow, brown eyes. Line on back. _Melita quinquedentata_ Shoem. L. 6.5 mm. Tide pools Aug. 29. _Allorchestes_ sp. immature. One lot pale green, red antennæ, L. 3.5 mm. One red L. 10 mm. One from holdfasts brown and red. L. 6 mm. _Hyalella azteca_ Sauss. Brown green, 3.5 to 4 mm.