290 Bulletin Vanderbilt Marine Museum, Vol. VII 



Class: AMPHINEURA 



Order: POLYPLACOPHORA 



Family: CHITONIDAE 



Subfamily: Chitoninae 



Genus: CHITON Linne 

 Chiton marquesanus H. A. Pilsbry 



■f 



Plate 110 



Type: Dr. Pilsbry's type was presented to the Philadelphia 

 Academy of Natural Sciences by the late Andrew Garrett and 

 was labelled "C. marquesana," but whether this name was given 

 by Mr. Garrett or Dr. Tryon was unknown to Dr. Pilsbry, who 

 presented the original description and figures of this exquisite 

 Chiton. His type, a unique, measures: length, 46 millimeters; 

 width, 26 millimeters. 



Text figure 15. — Transverse section of girdle of Chiton marquesanus 



Pilsbry, greatly enlarged. 



Distribution: Marquesas Islands (Pilsbry, Boone). 



Material examined: Two specimens, taken from the rocks 

 at Anaho Bay, Nuka Hiva Island, Marquesas Islands, Pacific 

 Ocean, August 10, 1931. 



Technical description : Colour: Dorsally dark olive green, 

 nearly black on the lateral areas and terminal valves. Girdle dark 

 green. Interior light blue, stained at the sinus and under the beaks 

 with purplish brown. 



Measurements: The smaller specimen has a length of 30 

 millimeters and a median width of 16 millimeters, the larger 

 specimen is 48 millimeters long and 26 millimeters wide. 



Shell: This chiton is oblong-ovate, depressed, obtusely cari- 

 nated, with the side slopes nearly straight. The surface appears 

 smooth and polished on the central areas and granulose and lustre- 

 less on the lateral areas, to the unaided eye. Under magnification 



