PHOLAS.— Plate IX. 



The Ti.r.KDiNiFOi;M Pholas. Shell globose, open, divided ] Sowerby. Proo. Zool. See 



in the middle by a serrated canal ; anteriorly sub- 



angulated at the ventral margin, ornamented with 



fluted concentric ribs ; posteriorly short, smooth ; 



dorsal plate single, subquadrate, placed npon the 



reflected margin of the valve?. 

 SowEiuiv. Proc. Zool. Soc, 18-19. 

 Huh. Cuba. 



This species which was found burrowed in floating 

 wax, and the Pliolas aperfa, so nearly resembling it, are 

 so short as to resemble Teredinm or Xyhiihafjw 

 ill general appearance. The valves of the former, 

 however, have no dorsal plates, and those of the latter 

 want the curved subumbonal processes, characteristics 

 of the true Pholades, of which the present species is 

 unquestionablj' one. 



Species 37. (Fig. a, h, Mus. Brit.) 



Pholas multistriata. Plio. icsid ohloii;/d, clmisd^ 

 fransrerse ante medium per canalem scmitiim divisd, 

 piirtc untied prope marginem ventralem Icevtgatd, 

 laten dorsali minutissime striata; parte posticd 

 Utriijatd, per laininas tumidas elongatd et acuminatd; 

 seiito dorsali ovali antice, semicircular!, j^osfice 

 suhacuininatd. 



The manv-striated Pholas. Shell oblong, closed, 

 transversely divided by a serrated canal in front of 

 the middle, anterior part near the ventral margin 

 smooth, at the dorsal side very minutely striated, 

 posterior part smooth, elongated and acuminated 

 by tumid laminse ; dorsal shield oval anteriorly, 

 rather pointed posteriorly. 



849. Thesaurus Con- 

 chyliorum. No. 10, Pholas, pi. 104, fig. 35, 36. 

 Hall. Turtle Island, North Coast of America. 



The striae on the umbonal part of this species are 

 exceedingly fine. The posterior part of the shell 

 appears lengthened out by lamina^ which are partially 

 distinct from tlie valves, yet form a ]iart of them. 



Species 38. (Mus. Cimiing.) 



Pholas quadrigonalis. Flw. testd clausd, suhcylindi-ica, 

 ventricosd, in partes tres oblique fransversales divisd ; 

 parte anticd prope marf/im in nidruli'in Iccrigatd, in 

 medio et ad dorsum minuti' sirintii ,• purte mcdiand 

 pland; parte posticd iiiid, riiiidc luniinis serratis 

 indutd ; marginis dorsalis inteijmnento suhtestaceo, 

 in partes quatuor, quarmn duas anticas breves, duas 

 posticus elongatas, irilohatas, diviso. 



The qu.^drigoxal Pholas. Shell closed, subcylindrical, 

 ventricose, divided into three obliquely transverse 

 parts ; anterior part smooth near the ventral 

 margin, minutely striated in the middle and at the 

 back; middle part flat; posterior part covered 

 with an epidermis in serrated layers ; integument 

 of the dorsal margin subtestaceous, divided into 

 four parts, of which the two anterior are short, and 

 the two posterior elongated, trilobate. 



Spengler ? 



Hal. ? 



Very little is known of the natural history of this 

 j very interesting shell, wliicli in some characters 



resembles Pholas Inci i. 



