578 GILBERT C. BOURNE. 
DESCRIPTION OF PLATE XXXVII, 
Illustrating Mr. G. C. Bourne’s paper “ On the Genus 
Monstrilla.” 
Lettering in the Following Figures. 
a. First antenna. ad'.—ad*. First to fourth abdominal segments. a. 9. 
Openings of the antennary glands. e. Hye. ez. Endopodite. ex. Exopodite. 
g. 4. Genital appendage. gz'. Cerebral ganglion. gz. Thoracic ganglion. 
m. Mouth. md. Mandible. ma. Maxilla. ov. Ovary. s.f'.—s./4. First 
to fourth swimming feet. v. d. Vas deferens. 
Fic. 1.—Monstrilla longispinosa, nov. sp., lateral view of an adult 
female. The genital appendage is cut off short. It is actually one and a half 
times the length of the entire animal. 
Fie. 2.—Ibid.?. ‘The first antenna, highly magnified. 
Fig. 3.—Ibid. The two abdominal segments and furca from below, 
showing the bifurcate genital appendage. 
Fie. 4.—Ibid. The opening of one of the antennary glands, highly 
magnified. 
Fie. 5.—Monstrilla anglica, Lubbock, ¢. Ventral view of the con- 
joint head and first thoracic segment, showing the median ventral eye, e.; the 
mouth, m.; the nerve-cord and ganglia, and the arrangement of the muscles. 
Fic. 6.—Ibid. The first antenna. 
Fic. 7.—Ibid.—The four abdominal segments and furea from above, 
showing the six furcal sete. 
Fie. 8.—Monstrilla rigida, I. C. Thompson, 2. Terminal part of 
genital appendage. 
Fie. 9.—Monstrilla anglica, Lubbock, ¢. Genital appendage. 
Fig. 10.—Monstrilla longispinosa, n. sp., 2. Fifth pair of swimming 
feet. 
Fie. 11.—Monstrilla rigida, I. C. Thompson, 2, juv. Mouth and 
rudimentary gnathites. Highly magnified. 
Fic. 12.—Ibid., I. C. Thompson, 9, adult. Ventral view of the hinder 
part of the thorax and the abdomen. 
Fic. 18.—Monstrilla Dane, Claparéde, 2. Dorsal view of cephalo- 
thorax, showing the ripe ovary. 
Fie. 14.—Monstrilla helgolandica, Claus, 2. First antenna. 
Fie. 15.—Ibid. One of the swimming feet. 
