GXATIIOPIIAUSIA GRACILIS. 185 



Distribufion. — Aceording to (lie literature this species is known from off 

 the West coast of Africa, "'Laos/' from the (!uh' of Mexico, the Baj- of Bengal, 

 the Arafm-a Sea, South of Mindanao, the Ha-waiian Islands, and is conniion in 

 the California region in the East Pacific. 



:;, Gnathophausia gracilis Willemoes-Suiim. 



1875. Gnatkophdiisin i/mcilix Willemoes-Sch.m, Trails. Linn.iSo(% London, .?cr. 2, 1, |). :>:!, \)\. 9, fig. 1. 



1885. Gnalh(>p}uinxia (jraciUs G. O. Sars, Challenger Kept., 13, p. 4S, jil. 7, ligs. O-IO. 



1S91. (IndUiitphduxiii hrcvispinU Wooii-M.'\soN & Alcook, Ann. Ma;;. Nat. lli.st., ser. G, 7, p. 209. 



1895. (liKilIiiiphiinsiii. biri'i.ipini.'i F.vxoN, Mcnn. Mus. Comp. Zoul., 18, p. 210, pi. ,J. 



1900. Giiathiijiliaiixid r/j«r(7/.s ()iiT.M.\.\'N', Proc. L'. S. Nat. Mu.x., 31, ]i. -iO. 



Sta. 40r>l. Nov. U, 1904. I.at . ."i° 17.1' S., long. 82° .59.7' W. 2222 fnis., trawl. 1 spoc-imen. 



Sta. -l(i.52. Nov. 11. 1901. Lat . 5° 4 1.7' S., long. 82'' 39.5' W. 400 fm.s. to .^urfai'c. 1 small .spci'irnrn. 



Sta.40.5(i. Xov. 13, 1904. Lat . 0° .54.0' 8., long. 8.3° 34.3' W. 2222 fnis., trawl. 1 spwinipn. 



Sta. 4709. Dec. 30, 1904. Lat. 10° 15.2' S., long. 9.5° 40. S' W. 2035 fins., trawl. 1 sppcinicn. 



.Sta. 4715. .Ian. 2,1905. Lat. 2° 40.4' S., long. 90° 19.3' W. On way up from 1743 fm.s. 1 .spefiincn. 



Ro/ifirh-s. — Tlie largest specimen, a male from Sta. 4709, is li',) mm. long; 

 a female with the mar.su])ium well developed (from Sta. 4().j()) is (i.") mm. long, 

 and another iemalc with marsupium (from Sta. 471.")) is (i2 mm. These' three 

 large specimens ha\'e on the gastric area an oblong, rather high, lamellar, sub- 

 triangular, dentate crest terminating in a spiniform process; besides they ha\-e 

 the lateral plates of the five anterior abdominal .segments expanded posteriorly; 

 the expansion of the plates of first segment is small in the twf) 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 

 2i5 nun., the anterior dorsal spiii(> on first abdominal segment is extremely small, 

 the lateral plates of the alxlominal segments are not exjianded 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 LnnielL-ir 

 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 Willemoes-Suhm and il. (). Sars; 

 it measures 41 mm. and is preserved in the British Museum. It has on the 

 gastric region a small, oblong, triangular, lamellar ])late with a spin(> on the 

 vertex and a little farther behind there are four small saw-like teeth in a longi- 

 tudinal row; furthermore the lateral ])lates of the abdominal segments are 

 feebly expanded nearly as in llie above mentioned specimen measuring 'AT mm. 

 Dr. Alcock loaned me the tyjie of G. I)rcri^jjiiuf:, and an examination gave the 



