68 



BIOLOGICAL RESULTS OF LAST CRUISE OF CARNEGIE 



DISTRIBUTION 



This species is known from the tropical part of the 

 Indian Ocean (lUig and Tattersall) and from the Eastern 

 Pacific (Hansen and Colosi). The present specimens are 

 from the same waters as the latter records. 



Doxomysis sp. ? 

 OCCURRENCE 



Station 99, latitude 04° 22' north, longitude 176° 23' 

 west, 50 m. May 2, 1929, one damaged specimen. 



REMARKS 



This specimen is too damaged to identify with cer- 

 tainty. Like D. quadrispinosa it has the abdomen spinu- 

 lose and it may be a mutilated example of this species. 



INCERTAE CEDIS 



Genus CARNEGIEOMYSIS, nov. 



DEFINITION 



General form robust and gibbous, abdomen flexed. 

 Carapace large, covering the whole of the thorax in dor- 

 sal view, produced laterally and posteriorly to cover the 

 whole of the first and half of the second abdominal so- 

 mites, produced anteriorly into a large triangular ros- 

 tral plate with a blunt apex, which partially covers the 

 eyes. Eyes very large, pyriform in shape in lateral 

 view, the cornea divided by a distinct groove into a larg- 

 er ventral part with smaller facets and a smaller dorsal 

 part with larger facets. Antennal scale rather short and 

 narrow, setose all round, with a distal part marked off 

 by a distinct suture. Thoracic limbs with the endopods 

 rather slender, that of the first thoracic limbs with a 

 feeble masticatory lobe on the second joint only, those of 

 the third to the eighth thoraiic limbs with the sixth joint 

 undivided. Telson short, entire, spatulate in shape, apex 

 armed with a few short stout spines, lateral margins with 

 a few spines distally. 



Type-Carnegieomysis xenops, n. sp. 



REMARKS 



The systematic position of this genus must remain 

 uncertain until male specimens are available for exami- 

 nation. The author anticipates that it will prove to be- 

 long to the Tribe Mysini, near to such genera as Aniso- 

 mysis, Idiomysis, and Lycomysis. It is a curious and 

 anomalous genus, recalling Idiomysis in its gibbous form 

 and abdominal flexure, but sharply distinguished from all 

 mysids known to the author by the large pyriform eyes 

 divided into dorsal and ventral parts by a groove. The 

 eyes resemble, in a general way, the eyes of some of the 

 Euphausiacea, such as Thysanoessa and Nematoscelis. 

 For the rest, the rather feeble and slender endopods of 

 the thoracic limbs, the undivided sixth joint of the endo- 

 pods of the third to the eighth thoracic limbs, and the en- 

 tire telson, together provide additional distinguishing 

 features by which the genus may be recognized. The 

 author is glad to associate this distinct form with the 



name of the vessel to whose researches its capture is 

 due. 



Carnegieomysis xenops, gen. and n. sp. 

 OCCURRENCE 



Station 148, latitude 24° 57' north, longitude 137° 44' 

 west, 100 m, October 19, 1929, one adult female. 



DESCRIPTION 



General form (fig. 4, p. 72) gibbous with the abdomen 

 flexed ventrally; lateral parts of the abdominal somites 

 covered with very small spinules; similar spinules scat- 

 tered over other parts of the body, particularly on the 

 anterior end of the carapace. 



Carapace relatively large, covering all the somites 

 of the thorax dorsally and produced laterally into a well- 

 marked wing partially covering the anterior abdominal 

 somites laterally; produced anteriorly into a broad 

 bluntly pointed rostral plate forming a hood partially 

 covering the large eyes dorsally and extending forward 

 to the level of the front of the eyes. 



Eves (fig. 4, p. 72) very large, brown in color, pyri- 

 form in shape viewed laterally, divided into a small dor- 

 sal part with larger corneal facets and a large ventral 

 part with smaller facets, the two parts separated by a 

 groove broader posteriorly than anteriorly, and devoid 

 of facets and therefore of pigment. The cornea appears 

 to be pushed in as a more or less circular depression in 

 the region of the groove, the depression affecting the 

 lower part of the dorsal section and the upper part of the 

 ventral section of the eye. 



Antennular peduncle with the second joint having a 

 well -developed, recurved finger-like process dorsally, 

 the process with two or three small setae at the apex. 



Antennal scale (fig. 5a, p. 72) small and narrow, 

 barely extending beyond the antennular peduncle, eight 

 times as long as broad, a small distal segment marked 

 off by a distinct suture, setose all round. 



Thoracic limbs . The general form and structure of 

 these limbs can best be seen from the figures (figs. 5b- 

 c, p. 72). The first thoracic limb (fig. 5b, p. 72) has a 

 small masticatory lobe on the second joint of the endo- 

 pod but none on the other joints. In the third to the 

 eighth pairs the sixth joint of the endopod is undivided 

 and armed with rather long plumose setae on the inner 

 margin. The nail is well developed in all the endopods 

 of the thoracic limbs. The basal joint of the exopod is 

 moderately expanded and has the outer distal corner 

 rounded, without a spine. 



Abdominal somites . The sixth abdominal somite is 

 more than twice as long as the fifth. 



Telson (fig. 5f, p. 72) a little shorter than the sixth 

 abdominal somite and narrower than this somite at the 

 base; about twice as long as broad at its base; lateral 

 margins rather abruptly narrowing for more than half 

 the leni^h of the telson and then diverging slightly to 

 form a spatulate distal part of the telson, ending in a 

 broadly rounded entire apex; the apex armed with five 

 quite short, rather stout spines more or less equidis- 

 tantly placed; lateral margins armed with three short 

 spines about the center of the margin just anterior to 

 the narrowest part of the telson. 



Uropods about twice as long as the telson; inner and 

 outer uropods equal in length; inner uropod without any 



