102 Mr. .Grdt^ on the GenerA ^ (ikvipedes, [^U4i 



CONCHOTRYA, GrOT/, ' 



Shelly plates, five ; two pair ventral, and one plate dorsal ; 

 peduncle ? 



Lives in holes in shells. 



C. Valentiana, Grai/, Shelly plates, thick, transversely lameU 

 lated. 



Inhabits Red Sea in the valves of Ostrea Cucullata, Bornj 

 Lord Vakntia, t 



BRTSNiEUS, Leach J without character. 



Shelly plates, seven ; three pair lateral, and one valve dorsal. 

 Body cyhndrical conical. Peduncle or base ? 



Living in holes in stony corals ; the holes are clean without 

 any shelly deposit. 



J3. rodiopus. Leach, Shelly valves, all transversely lamellar* 

 Mus, Brit, 



IL Annectcmt Group? Body conical, cylindrical. Shelly 

 valves, four, or six, or eight, articulated together laterally^ ana 

 sometimes to a shelly cup, called the support, which closes the 

 front of the shell, the hinder part closed by an operculum formed 

 of two or four valves, which leave an aperture for the passage of 

 the feet; the shelly valves increasing only at their broadest or 

 anterior edge. Attached immediately to or imbedded in marin« 

 bodies. 



Obs. The operculum appears to represent the posterior and 

 posterior ventral valves of the former group. 



Fam. in. Pyrgomatid^, Groy. 



Body, four, or six-valved; operculum four-valved, oblique, 

 valves articulated together ; base shelly, concave, cup-shaped. 

 Living imbedded in zoophytes. 



Each genus of this family appears to be peculiar to a certain. . 

 genus or group of zoophytes. 



^Shelly valves of the hody, four, sometimes united together. 

 Living; buried in stony corals. 



1. Pyrgoma, Savigny, AISS, Leach (n. 15). 



Valves of the body of the shell 4, soldered together ; sheath 

 of the operculum very small ; operculum conical, four-valved, 

 ventral valve linear, posterior valves hooked narrow triangular. 



P. cancellata. Leach. Shell radiately ribbed. 



P. lobata, Gray, Shell concentrically striated, deeply lidbed. 



2. Daracia, Gray,* Savignium, jLe«cA, without character. 



Valves of the body of the shell, four, soldered together ; sheath 



• Although I have*heen desirous from courtesy to preserve even the manuscript 

 of Dr. Leach, I have here been necessitated to change one, as itj^ against the- 



ntks of zoological n om e n c la t tii«» 



