GNATHOPHAUSIA GRACILIS. 185 
Distribution.— According to the literature this species is known from off 
the West coast of Africa, ‘Laos,’ from the Gulf of Mexico, the Bay of Bengal, 
the Arafura Sea, South of Mindanao, the Hawaiian Islands, and is common in 
the California region in the Hast Pacific. 
3. Gnathophausia gracilis Wititemoiis-Suum. 
1875. Gnathophausia gracilis W1LLeMoiis-Suum, Trans. Linn. Soe. London, ser. 2, 1, p. 33, pl. 9, fig. 1. 
1885. Gnathophausia gracilis G. O. Sars, Challenger Rept., 13, p. 48, pl. 7, figs. 6-10. 
1891. Gnathophausia brevispinis Woop-Mason & Atcock, Ann. Mag. Nat. Hist., ser. 6, 7, p. 269. 
1895. Gnathophausia brevispinis axon, Mem. Mus. Comp. Zodl., 18, p. 216, pl. J. 
1906. Gnathophausia gracilis OrrTMANN, Proc. U.S. Nat. Mus., 31, p. 39. 
Sta. 4651. Nov.11,1904. Lat. 5° 47.1’S., long. 82°59.7’ W. 2222 fms., trawl. 1 specimen. 
Sta. 4652. Nov. 11,1904. Lat. 5° 44.7’S., long. 82° 39.5’ W. 400 fms. to surface. 1 small specimen. 
Sta. 4656. Nov.13,1904. Lat. 6°54.6’S., long. 83°34.3’ W. 2222 fms., trawl. 1 specimen. 
Sta. 4709. Dec. 30,1904. Lat. 10° 15.2’ S., long. 95° 40.8’ W. 2035 fms., trawl. 1 specimen. 
Sta. 4715. Jan. 2,1905. Lat. 2° 40.4’S., long. 90° 19.3’ W. On way up from 1743 fms. ‘1 specimen. 
Remarks.— The largest specimen, a male from Sta. 4709, is 69 mm. long; 
a female with the marsupium well developed (from Sta. 4656) is 65 mm. long, 
and another female with marsupium (from Sta. 4715) is 62 mm. These three 
large specimens have on the gastric area an oblong, rather high, lamellar, sub- 
triangular, dentate crest terminating in a spiniform process; besides they have 
the lateral plates of the five anterior abdominal segments expanded posteriorly ; 
the expansion of the plates of first segment is small in the two females, moder- 
ately large in the male, and the expansions increase in all three specimens 
gradually and considerably in size from first to fourth segment, while those of 
the fifth segment are somewhat smaller. In the smallest specimen, measuring 
25 mm., the anterior dorsal spine on first abdominal segment is extremely small, 
the lateral plates of the abdominal segments are not expanded posteriorly, 
and the lamellar crest on the gastric area is rudimentary with a small spine 
above; in the fifth specimen, which is 37 mm. long, the last-named lamellar 
crest is developed nearly as in the large specimens, but the lateral plates of the 
second to the fifth abdominal segments are very feebly expanded. 
I have examined the type-specimen of Willemoés-Suhm and G. O. Sars; 
it measures 41 mm. and is preserved in the British Museum. It has on the 
gastric region a small, oblong, triangular, lamellar plate with a spine on the 
vertex and a little farther behind there are four small saw-like teeth in a longi- 
tudinal row; furthermore the lateral plates of the abdominal segments are 
feebly expanded nearly as in the above mentioned specimen measuring 37 mm. 
Dr. Alcock loaned me the type of G. brevispinis, and an examination gave the 
