297 



Fig. IKS 



1. Inner surface of 1" redwood sheathing, submerged 20 months in Pearl Harbor. Martesia striata 

 coming through from outside. Looking through empt\- burrows, note small openings through which 

 borers entered. At upper left is seen a strip of tarred ship's felt which they have penetrated. 



iPholo by courtesy of Public H'oc^s Dept., V. S. Naval Station, Hawaii.) 



2. Side and dorsal views of Alarlcsia striata, natural size. 



Martesia striata 



While Maitcsiu striata is not, properly speaking, a "shipworm," as a wood boring 

 mollusk of similar habits and capacities for damage it may well be considered here. 

 It is an organism somewhat resembling a small clam in general appearance, blunt at 

 the anterior end and tapering somewhat posteriorly. The anterior end may be open, 

 exposing the foot, or the gap may be closed by a smoothly roimded calcareous parti- 

 tion, consisting of two halves separated by a median fissure (see fig. 117, J). The latter 

 condition indicates that the organism has for a time at least suspended boring activi- 

 ties. The species, M. striata, is characterized by a narrow accessory plate along both 



