276 PEOCEEDINGS OF THE ACADEMY OF [1889. 
species is a remnant of tlie originai ligament or a mere epidermal 
extension 
The length of thè contraeteci specimen examined was 270'0 mm. 
It was obtained on thè Florida coast. 
Very different in some particnlars is thè macroscopic anatomy of 
ZirpluBci crispata of which a specimen, nieasuring in its contracted 
state 260.0 mm., is before me. It was obtained by Dr. R. E. C. 
Stearns, in Puget Sound, Washington Territory. In this species thè 
siphonal tube is covered with a dehiscent thin papery epidermis, as 
in 3Iya. and is about three times as long as thè rest of thè animai, 
proportionally thicker, more cylindrical and consequently more 
bluntly pointed than in P. costata. There are no important differ- 
ences in thè ])edal opening where thè curtain is dose to, if not 
coalescent with, thè margin of thè mantle. The ventral portion of 
thè visceral mass is not flattened and marginated, as in P. coStatus, 
but is produced into a point behind. Above this point there is no 
sensory appendicle. The palj)i are mudi as in P. costatus and 
similarly sujiported by thè umbonal apoph}t5Ìs on each side, but thè 
lower or inner palpus is much less fleshy. The gills join behind thè 
body but thè junction is not floored across and hence there is no 
separation of thè anal and branchial chambers, nor does tbe siphonal 
septum make its appearance where thè siphon begins. On thè con- 
trary thè siphon incloses but a single tube and only at about thè 
distai third of its length does any division or partition appear. All 
this distance thè somewhat attenuateci gills extend, nearly fillingthe 
tube, and uniteci at their bases. The gills on each side consist of a 
AV-shaped pair ofsacs, but thè outer stem of thè W is not produced 
into an appendicular lamella as in P. costatus. The anus is thin- 
edged with a valvular infolding of thè eclge but less cup-shaped than 
in P. costatus. Following thè line which would bave been taken by 
thè siphonal septum, had it existed, are two double-edged, little- 
elevatecl ridges. It is probable that thè stem of thè gills so ex- 
pandecl in life as to conduct thè effete iiroducts of thè intestine to 
thè anal tube of thè siphon without allowing them to come in con- 
tact with thè respiratory face of thè gills. Taken as a whole 
Zirphcca seems more moclified than Pholas and shows fewer traces 
of thè Mijacean type from which both are probably descencled. 
I bave not found a description of thè soft parts of these two 
species, after some search in thè text books, and so bave thought it 
well to put them on record. 
