1420 



Otto, Sara V. 1973. 



Hermaphroditism in two species of pelecypod mollusks. Proc. Natl. Shellf. 

 Assn. 63: 96-98. 



One bilaterally hermaphroditic hard clam was found in Chincoteague Bay from 

 546 clams examined. Phagocytic infiltration was heavy throughout the clam 

 indicating physiological stress. Of 520 clams examined from Chesapeake Bay, 

 no hermaphrodites were found. - D.L. 



1421 



Otto, Sara V. 1975. 



D.N.R. readies new facility for shellfish studies. Comm. Fish. News, Md. Dept. 

 Natural Resources 8(6): 1. 



A trailer was being modified for use as a field office and laboratory. The 

 facility was expected to assist in providing further information on shellfish 

 diseases, such as the Amorphous Blue Bodies condition in hard clam, caused by 

 the parasite Chlamydia, which infests one or several cells in the lining of 

 digestive gland tubules, then reproduces in tremendous numbers. - J.L.M. 



1422 



Otto, S. V., J. C. Karshbarger, and S. C. Chang. 1975. 



Clamydia infections in clams. 1. Incidence, distribution and histopathology . 

 Soc. Invertebr. Pathol., Ann. Meeting (8th). Corvallis, Oregon: 29 (abstract). 



We were not able to find the volume that contained this abstract. - J.L.M. 



1423 



Owen, G. 19 53. 



The shell in the Lamellibranchia. Quart. J. Microscop. Sci . 94: 57-70. 



Venus is mentioned, but the species is not identified. In lamellibranchs 

 generally, direction of growth at any region of the valve margins may be 

 resolved into: a) a radial component radiating from the umbo and acting in 

 the plane of the generating curve; b) a transverse component acting at right 

 angles to the plane of the generating curve; and c) a tangential component 

 acting tangential to, and in the plane of, the generating curve. The radial 

 component is always present and affects the form of both valves; the trans- 

 verse component may be reduced or absent in one valve. The mantle and shell 

 are oriented with reference to the normal axis, which follows that sector 

 of the shell secreted by the normal zone of the mantle edge (where the effect 

 of the transverse component is- greatest) and passes through the umbo, the 

 normal zone and the point at which the greatest transverse diameter of the 

 shell intersects the surface of the valves. The form of shell valves should 

 be considered in reference to the outline of the generating curve, spiral 

 angle of the normal axis, and form (planospiral) of the normal axis. "De- 

 flection" anteriorly of the umbones and splitting of the ligament in many 

 bivalves is a consequence of a tangential component affecting the form of 

 both valves. The turbinate spiral shell in gastropods and lamellibranchs is 

 the resultant of two differential growth ratios, which in lamellibranchs act 

 respectively perpendicularly to the plane of the generating curve, and in 

 the plane of the generating curve. - modified author's summary - J.L.M. 

 and M.W.S. 



398 



