38 



ALLAN HANCOCK PACIFIC EXPEDITIONS 



VOL.8 



largest, longer than wide, proximal margin convex, distal margin deeply 

 concave; lateral margins concave, bearing 3 or 4 reduced tentacle scales, 

 outermost being the largest. Second plate rectangular, broader than long, 

 proximal margin almost straight, distal margin concave, lateral margins 

 bearing 2 short, broad tentacle scales. Third plate rectangular, only 

 slightly broader than long, lateral margins bearing 2 short tentacle scales, 

 outermost largest. Fourth to 8th plates hexagonal, much wider than long; 

 4th, 5th, and 6th bearing a minute tentacle scale on the distal lateral 

 angle. Succeeding plates pentagonal or oblong, small, becoming triangular 

 and smaller distally, until they occupy only %. of the arm segment or less 

 at the extremities. The 6 basal plates are separated by a deep concavity, 

 succeeding plates separated by side arm plates; distally the separation be- 

 comes even greater. 



Color. — Dried from alcohol, disk white with a lavender tinge, arms 

 light cream color. In life, upper surface variegated with light and dark 

 red, or red and yellowish, or red and white; oral surface white. The 

 larger specimens are not deeply colored. 



Types. — Holotype, AHF no. 12; 60 paratypes, 16 in M.C.Z. 



Type locality. — Holotype and 33 paratypes, 16 in the Museum of 

 Comparative Zoology, from Station 792-38, 70-80 fms., off Daphne 

 Minor Island, Galapagos, January 20, 1938; 2 paratypes from Station 

 191-34, 70 fms., Lat. 0° 55' S., Long. 90° 39' W., January 26, 1934; 

 and 25 paratypes from Station 190-34, 58-60 fms., Lat. 0° 55' S., Long. 

 90° 30' W., January 26, 1934. 



Remarks. — This species is closely related to A. paucisquama but dif- 

 fers as f ollovi^ : 



A. irregularis 

 No symmetrical rosette on disk 



All plates finely granular 



Plates flat or slightly swollen 



Radial shields large 



Disk flat, 1.5 mm. thick 



Arms about 2.2 times disk diame- 

 ter, not slender distally 



A. paucisquama 



A symmetrical rosette on the disk 

 composed of a central pentago- 

 nal plate and 5 larger, equal ra- 

 dial plates 



Disk and basal arm plates deeply 

 pitted 



Plates convex, basal upper arm 

 plates almost hemispherical 



Radial shields small 



Disk elevated, 3.5 mm. thick 



Arms short, 1.8 times disk diame- 

 ter, becoming very slender dis- 

 tally 



.f 



