116 BULLETIN OF THE 



Saxicava azaria n. s. 



Shell having much the aspect of Potamomya ; thick, of earthy texture, ex- 

 tremely inequivalve, marked with coarse irregular concentric ridges and growth 

 lines, covered with a strong brown wrinkled epidermis, irregularly inequilat- 

 eral ; left valve the smaller, with the posterior side shortest, right valve with 

 the posterior side longest and strongly twisted to the left ; umbones very 

 prominent, Corbula formed, anteriorly directed and greatly involute ; upper sur- 

 face in front of them obscurely flattened ; from behind them two indistinct, 

 irregular coarse ridges extend to the posterior end, which is obscurely rostrated 

 and twisted to the left ; ligament coarse, stout, external ; cardinal margin per- 

 fectly edentulous, irregularly twisted ; other internal margins thin, smooth ; 

 interior livid white ; muscular impressions irregularly broken and blotchy, as 

 in Saxicava and certain species of so-called Panopcea; posterior end somewhat 

 gaping. Lon. 25.0 ; alt. of larger valve, 22.0 ; diam. 16.5 mm. 



This extraordinary shell, which has all the appearance externally of a gi- 

 gantic irregularly twisted Corbula, was obtained by the U. S. Coast Survey 

 Steamer Bache, twenty miles off Charlotte Harbor, Florida, in thirteen fathoms, 

 April 19, 1872. Many of its peculiarities are doubtless merely individual ; 

 but, allowing all that may be claimed on this score, it does not appear to even 

 approximately resemble any other species of Saxicava known to science, al- 

 though it pretty certainly belongs to that genus. It was alive when taken, but 

 the soft parts were not preserved. 



Modiola polita Verrill and Smith. 



M. polita V. and S., Am. Journ. Sci., XX. p. 400, Oct. 25, 1880. 

 ? Mytihis luteus Jeffreys' Rep. on French Expl. in the Bay of Biscay, pp. 5, 6 ; in 

 Rep. Brit. Assoc. Adv. Sci., 1880. 



Station 43, 339 fins., etc. 



A species of Modiola, or perhaps of Modiolaria ; agreeing with the very brief 

 diagnosis of Messrs. Verrill and Smith, as far as that goes, and with the 

 habit of Dr. Jeffreys' undescribed Mytilus in forming a large nest, or mat, 

 of byssus-threads, like most Modiolarise ; was obtained at various depths and 

 localities, reachim.' to very deep water, the largest specimens from the di 

 water being over two inches in length. The depths are not given in Dr. Jef- 

 freys' paper. Prof. Verrill's specimens were from 238 fathoms. 



Crenella decussata Montague. 



. op. eii., p. SI, Tub. ::, fig, (. i - 

 WwulocarcHa divwricaia D'Orbigny, Sagra, Moll. Cab., II. p. 811, Tab XX VII. 

 figs. 56-69 (1846). 



Barbados, 100 fms. [Alaska, California, New England, British Bean, Nor- 

 way, etc. | 



