49 Mr. J. W. Jackson on Lusitanian 
and the Mediterranean var. emarginata are closely related. 
The latter is very distinct in shell-characters from the typical 
North-Atlantic 7. caput-serpentis, and merits its distinctive 
name, The same may be said of the Dabai form, and for the 
purpose of easy reference it might be known as var. abbre- 
viata, NOV. 
T. caput-serpentis is widely distributed along the eastern 
side of the Atlantic Ocean, being recorded from off the coasts 
of Norway, British Isles, France, Spain and Portugal, 
Canaries, and West Africa. It is represented at the Cape 
Verde Islands by a variety (var. germana) * intermediate 
between the type and 7. septentrionalis. 
In the Mediterranean it is recorded from many stations in 
the western portion, but appears to be altogether absent in a 
recent state in the eastern part. 
According to Fischer and Oehlert (op. cit. p. 35) the 
Species appears to have a very extended fossil distribution, 
ranging from Miocene to recent times. The principal 
localities are in the Mediterranean region: N. Italy (Lower 
Miocene and later), 8. Italy and Sicily (Lower Pliocene and 
later), Provence (Pliocene), and Algiers (Pliocene). It has 
also been cited by authors for the Miocene of Morea, Sicily, 
Switzerland, and the Azores. Ancestral forms are known 
from the HKocene (often given as vars. of J’, caput-serpentis, 
especially in N. Italy Tt), and from the Cretaceous. 
OF the three specimens of Miihlfeldtia from Dabai one 
agrees very closely with examples of Jf. truncata from Medi- 
terranean localities. Compared with specimens from Messina 
(Sicily) and Sardinia, no distinct points of difference can be 
noted, either in outward appearance or in the development 
of the loop. This specimen measures :—Length 12°7 mm., 
breadth 15°8, thickness 6°8 mm. 
The two remaining examples differ somewhat from typical 
M. truncata in certain characters. Though these differences 
may be only of varietal rank, it might be advisable to give a 
full description of the form in question to enable it to be 
traced in other collections. In order to distinguish it, I 
propose to call it var. paucistriata, nov. 
The more perfect of the two specimens is somewhat 
smaller than average MZ. truncata, being length 9°2 mm., 
breadth 11°6, thickness 4:4, and may be described as 
* Fischer and Oehlert, op. cit, 1891, p. 53, pl. i. fig. 4, af. 
+ Sacco, ‘I Brachiopodi dei Terreni Terziarii del Piemonte e della 
Liguria,’ 1902, p. 26. 
