26 Sirst Annual Report 
the cloaca. Along the base of the oviducts on each side (dorsally) 
may be seen the kidneys ( Figure 2 A), each of which gradually 
diminishes in size, ending about the middle of the oviduct. Along the 
anterior and ventral side (appearing on top in figure) of the oviducts 
are the ovaries, attached throughout their anterior part to the ovi- 
ducts and posteriorly to the rectal gland, (Figure 2 R). The ovaries 
and oviducts appear entirely out of proportion in the figure on 
account of the large ova in the latter. Aside from this the relation- 
ships of the various organs may be seen from the figures. The 
oviducts, instead of being separated as shown, normally extend dor- 
sally over the stomach (as the fallopian tubes) and then down 
around the cesophagus in front of the liver, fusing below except for 
the common opening into the abdominal cavity. 
The male urogenital organs of Rhinobatus productus resemble in 
general those of the same sex of Aetobatus californicus, as noted 
under that species, except that in the specimen examined the testes 
are well separated and distinct throughout their length. 
On August 14th a female of this species was taken just as she 
vas about to bear young. In fact, two of the latter were just emerg- 
ing from the cloaca. The brood consisted of four males and one 
female, all of the same size. The mother was a large specimen, 
measuring 119 em. in length, and 384 em. across the pectorals. In 
addition to the five young she contained seven well developed ova, 
each as large as a hen’s egg. It is possible that she had already 
given birth to some young in the water before being caught. 
The following notes were taken on the five young secured: All 
were alive and normal; the tail of one and head of another were pro- 
truding from the cloaca at the time of capture, indicating that they 
may be born either head or tail foremost. Only this one individual, 
however, appeared tail foremost. All five were of the same stage 
of development, with no signs of yolk-sae or other embryonic attach- 
ments. One of the males gave the following characters, with which 
the others essentially agreed: Measurements in mm. Length, tip 
to tip, 238; to spiracles, 35; to eyes, 37; to base first dorsal, 145; to 
mouth, 47; to base second dorsal, 180; to posterior tip of pectoral, 
104; width mouth, 16; interorbital, 11; breadth across pectorals, 88; 
tip snout to first gill opening, 56; to vent, 112; length ventrals, 36; 
height first dorsal, 18; second, 18; length caudal, 34; distance be- 
tween two anterior gill openings, 39; two posterior, 26; length clasp- 
ers, 16, not quite reaching ventrals. Twenty-two spines along back 
in front of first dorsal; seven more between dorsals, and two small 
ones behind second dorsal; two spines on each shoulder opposite 
fourth dorsal spine, about on a line with inner and outer borders of 
orbit respectively ; a row of six spines above inner margin of orbit, 
