178 MORRILL. [Vol. XI, 



The food of these fish consists of crabs, shrimps, and small 

 fish (14), but they will eat pieces of beef, fish, or shark, and are 

 particularly fond of pieces of clam or snail. 



They are very plentiful at Woods Holl during their spawning 

 season, the latter part of May and the first of June. P. pal- 

 mipes occurs in much greater numbers than P. cvolaiis. 



The pectoral fins, in both species, are very large, being about 

 one-third as long as the body and nearly as broad as long. They 

 extend horizontally from the sides of the body, when expanded, 

 somewhat in the manner of wings, and it is owing to this that 

 they have received the common names of brown-winged and 

 red-winged sea-robins, according to the color of the fins. 



They are also known as flying-fish. The term "grunter," 

 which is often applied to them, has reference to the peculiar 

 sounds produced when disturbed. 



Nervous System. 



The central and peripheral nervous system of both species 

 of Prioiiotiis were studied by dissections and macerations. 



The differences between the two species are so small as far 

 as the general arrangement is concerned, that a description 

 will only be given of the species figured (/'./^/^wz/^j-, PI. XII, 



Fig- 3)- 



The most noticeable feature of the central nervous system 



and the only part which will be considered here is the series of 



paired enlargements, six in number, on the dorsal surface of 



the spinal cord. These enlargements, or " accessory lobes " as 



designated by Ussow (10), Fig. 3, ac.L, are associated with the 



origin of the sensory roots of the first three pairs of spinal 



nerves (I, II, and III). The two anterior pairs of lobes are 



very indistinct ; in most cases the third pair is well developed, 



and the fourth and fifth are closely crowded together as if they 



had at one time been united. The posterior pair is much larger 



than any of the others. The first spinal nerve (I) arises from 



the first and second pair of "accessory lobes"; the second 



spinal nerve (II) from the third pair, and the extremely large 



third (III) receives fibers from the last five pairs of lobes. 



