1457 



Perkins, George H. 1869. 



Molluscan fauna of New Haven. A critical review of all the marine, fresh- 

 water, and land Mollusca of the region, with descriptions of many of the 

 living animals and of two new species. Proc. Boston Soc. Nat. Hist. 13: 

 Part II. Lamellibranchiata: 139-164. 



Veneridae; Crassivenus nov. gen. Crassivenus mercenaria nobis. Venus 

 mercenaria Linn., Syst. Nat., 1131; Lam., An. sans Vert., Vol. VI, p. 346; 

 Gould, Invert. Mass., p. 85, fig. 67; De Kay, Moll. N.Y. , p. 217, pi. xxvii, 

 fig. 276. Common round clam. Occurs abundantly in sand just below low tide 

 level. Animal with mantle open freely, except behind, where it is united to 

 form two very short siphons, which are blackish, fringed at the ends, bright 

 yellow inside; the mantle is thickened and ruffled at the edge, yellowish 

 white; gills, two pairs, greenish white, oblong-ovate, somewhat pointed 

 behind, hanging obliquely, inner a little larger; foot rather large, when 

 contracted broad and short, strongly striated, somewhat crenulate on lower 

 edge, which is sharp, broadest before and obtusely rounded behind, pointed 

 bluntly, color buff yellow; palpi lanceolate, smooth without, striated 

 within; muscles pink on inner side, white on outer, anterior pear-shaped, 

 posterior ovate. Measurements: length of shell 77 mm, breadth 71 mm, 

 height 54 mm; length of foot 37 mm, breadth 15 mm anteriorly; length of 

 gills 23 and 29 mm, breadth 15 and 16.4 mm; length of palpi 12.6 mm, 

 breadth 7 mm; length of siphon tube 14 mm, breadth 8 mm. As, according to 

 British Association rules, no specific name can be made generic, those 

 formerly given to this and the next species (Totteniana gemma) do not hold. 

 I therefore propose the names here given. - verbatim quotation from 

 original, except for slight changes in punctuation and abbreviations, 

 where' necessary to change format. - J.L.M. 



1458 



Perry, C. A. 1940. 



Comments on Mr. Bidwell's paper: A review of bacteriological shellfish 

 scoring. Conv. addresses, Natl. Shellf. Assn., 5 p., not numbered. 



Bidwell concludes that coliform densities in sea water represent a "fair 

 measure of pollution". The author believes that E. coli offers a sounder 

 measure. His data show that a coliform score of 50 (MPN 2400) would allow 

 about 1/4 of polluted hard clams to go to market. There is little doubt 

 that crude coliform scores represent temperature effect and do not necessarily 

 bear any relation to pollution. It might be concluded that a limiting score 

 of 5 would be reasonable for hard clams in the low score period. A limiting 

 score of 50 for shucked hard clams seems satisfactory. - J.L.M. 



1459 



Perry, Louise M., and Jeanne S. Schwengel. 1955. 



Marine shells of the western coast of Florida. Paleontol. Research Inst., 

 Ithaca, N.Y., 318 p. 



Mercenaria lives on sandy bottoms buried beneath the surface with siphons 

 extended upward into the water. Natica, Polinices , Terebra, Conus, Nassarius, 

 Cantharus, and JJro salpinx move freely about, preying largely on these bivalves. 

 Busy con and Fasciolaria are found wherever Mercenaria campechiensis is present. 

 Phylum Mollusca, Class Pelecypoda, Order Teleodesmacea, Family Veneridae is the 

 largest pelecypod family in numbers of genera and species, and of widest 

 distribution in depth and range. They are native to all seas, and wherever 

 man has found them he has used them for food and the shells for use and 

 ornament. They are burrowers but do not dig deeply and move about freely with 

 a flattened tongue-shaped foot. Mercenaria campechiensis (Gmelin) /Venus 

 campechiensis Gmelin/: Alt 100 mm, length 110 mm, is size of average adult 

 shell, but some are much larger and heavier; shell grayish white, heavy, thick, 

 solid and porcelanous ; inequivalve; umbos far forward; strong external 

 ligament; lunule and escutcheon well defined; margins rounded; sculpture of 

 close lamellar concentric ridges; hinge margin thick, with strong cardinal 



407 



