POLLICTPES. 79 



Terga subrhomboidal, broad, smooth, with the basal angle widely truncated, and 

 equalling in breadth half the length of the occludent margin ; the basal truncated side 

 forms a right angle with the scutal margin : the uppermost part of the scutal margin forms 

 a broad, rounded, slightly projecting point. 



Oxford Clay; Christian Malford and Chippenham, Wilts. Mus, J. Morris. 



This species has been named by Mr. Morris, as it appears to me, from the terga alone, 

 which are well figured by him and by Mr. Sowerby : these valves (an inspection of two of 

 which from Chippenham, I owe to the kindness of Mr. Morris,) are certainly quite distinct, 

 in the extent to which the basal angle is truncated, and in the degree of projection of the 

 uppermost part of the scutal margin, from any others which I have seen ; but had they not 

 been already named, according to the rule followed here, they Avould have been passed 

 over. 



Terga subrhomboidal, or strictly pentagonal, rather broad, very flat and thin ; basal 

 angle truncated, extraordinarily broad, equalling half the length of the occludent margin, 

 at right angles to the scutal margin ; no single distinct ridge, or furrow, runs from the 

 apex to the broad basal angle : upper and lower carinal margins nearly equal in length : 

 occludent and upper carinal margins meet each other at right angles : occludent margin 

 rather shorter than the scutal margin ; with the uppermost portion of the latter slightly 

 projecting in a blunt, rounded point, which corresponds with a just perceptibly convex slip 

 of valve, extending along the occludent margin in the manner so common in this genus. 

 Internally, the surface is smooth ; scarcely even the smallest part of the apex could have 

 projected freely. 



Largest specimen nearly a quarter of an inch in length. 



[Published species of LepadidcB of a doubtful nature, owing to vatccs, not typical, having 

 been named, or from the specimens having been imperfect, or from the shortness of the 

 descriptions.] 



Anatifera turgida. Professor Steenstrup (in Kroyer's Tiddskrift, 2 B. (1839), PI. V, figs. 4 — 5,) has 

 thus named some valves from Scania: he states that the scuta resemble in their growth those of Cineras, 

 or his Anatifera cretcv, that is the Scalpellum ? cretcB of this work. Therefore, I conclude that these valves 

 cannot properly be ranked under Anatifera or Lepas. 



Anatifera convexa. Roemer, Norddeutscli. Kreidegebirges, Tab. XVI, fig. "• I do not consider tlie 

 evidence nearly sufficient to place the valve here described in the genus Anatifera ; it might be one of the 

 lower Latera of a species allied to PolHcipes rjloher or unijuis. Pictet (Traite Elementaire de Paleontologie. 

 Tom. Ill, p. 438) states that the specimen in question is Aj)ttjclius cretaceus. Several vague notices of 

 fossil species of Anatifera or Lepas have appeared at various times, but they hardly seem to deserve notice. 



