404 DR. GWYN JEFFREYS ON MOIXUSCA OF THE [Apr. 16, 



furnished at its edges with short and very delicate close-set cilia of 

 different lengths and sizes, which project somewhat beyond the 

 valves, as in T. caput- serp entis. 



The tubercles which close the tubular perforations in the shell 

 are extremely small and numerous. In some large and unusually 

 thick valves dredged by Dr. Carpenter in H.M.S. 'Shearwater,' off 

 the coast of Tunis, the perforations are irregular or unsymmetrical, 

 as in T. grandis. 



Var. 1. minor, Philippi, = 2 1 . affinis, Calcara. 



' Porcupine ' Exp., 1*70 : Mediterranean, St. 58, 266 f. 



Off Jan Mayen's Isle, 263 f. (Friele, as T. arctica) ; Mediter- 

 ranean, Adriatic, and iEgean, 30-310 f . ; 'Challenger' Exp., off 

 Cape of Good Hope, 150 f., and Azores, 1000 f. ; ' Josephine ' Exp., 

 off Yilla Franca, Azores, 320-600 f. ; Japan, 55 f. (A. Adams, as 

 T. davidsoni). 



In a specimen of this variety from the Bay of Naples the front 

 margin is cloven or deeply indented, apparently in consequence of 

 the mantle having been injured in that part. 



Var. 2. sphenoidea, Philippi. (Plate XXII. fig. 6.) 



'Porcupine' Exp., 1870: Atlantic, St. 16, 994 f., 24, 292 f. ; 

 25, 374 f. 



Gulf of Florida, 100-270 f. (Pourtales, as T. cubensis). 



After a protracted and very careful examination of my specimens, 

 which I had considered the 1\ sphenoidea of Philippi, and having 

 compared them with fossil specimens sent me by Professor Seguenza 

 as Philippi's species from the Sicilian Tertiaries, as well as with a 

 series of T. cubensis which I received from Count Pourtales and Pro- 

 fessor Alexander Agassiz, and also after a close comparison of all these 

 specimens with the description and figures given by Philippi, 

 Seguenza, Pourtales, and Dall, I am convinced that T. sphenoidea 

 and T. cubensis are the same, and constitute a well-marked variety 

 of T. vitrea. The loop in T. sphenoidea and T. cubensis is precisely 

 similar. The shape and proportions of the loop depend on the 

 shape of the shell in T. vitrea, and, I believe, in every other species 

 of Terebratula. Some recent and fossil specimens of this variety 

 exhibit more or less distinct, although slight, longitudinal striae, 

 which radiate from the beak and are especially visible at the sides ; 

 and the same kind of sculpture is occasionally observable in speci- 

 mens of the typical form of T. vitrea. 



As to synonyms, 1 cannot recognize any valid character that would 

 serve to distinguish Seguenza's Sicilian Tertiary species, T. elliptica 

 and T. michelottiana from T. vitrea, or his T. miocenica, T. orbicu- 

 lata, and T. benoitiana from the variety sphenoidea. T. manticula 

 of Fischer (Journ. Conch, t. xvii. p. 81, pi. iii. fig. 4), a Miocene 

 fossil of the south-west of France, seems to be closely allied to the 

 variety minor, the only difference being that the deltidium in the 

 fossil is larger. T. cernica of Crosse, from the Mauritius (Journ. 

 Conch, t. xxi. p. 285, and xxii. p. 75, pi. i. fig. 3), may be also the 

 present nearly ubiquitous species. 



Costa, in his ' Fauna del Regno di Napoli,' refers the T. 



