GONZALES & GOSLINER: NEW SPECIES OF PHILINE FROM THE INDO-PACIFIC 355 
Rougemont 2008) random starting trees, using 10,000 rapid bootstraps. The model of analysis was 
set to GTR + Gamma with Scaphander mundus as the outgroup. 
Genetic distances: In order to compare the genetic distances among specimens oiPhiline from 
different biogeographic areas, we calculated the mean genetic distances for the molecular marker 
using PAUP* 4.0 b 10.0. We followed the criteria applied by Krug et al. (2012) who concluded that 
mean intraspecific difference for the 16S gene was generally less than 0.5% while inti*aspecific dif¬ 
ferences ranged from 1.5%-5.9%. We considered any divergences in the 16S gene exceeding 2% 
to represent distinct taxa. 
Species Descriptions 
Cephalaspidea Fisher, 1883 
Family Philinidae Gray, 1850 
Genus P/i///w^Ascanius, 1772 
Type species: Bulla aperta Linnaeus, 1767, by subsequent designation 
Philine acuticauda Gonzales and Gosliner, sp. nov. 
Figures lA-B, 2-3 
Material Examined.— Holotype: CASIZ 192085, ST HEPD 05, beam trawl in fine mud, 
459^96 m depth, western end of Verde Island Passage, Balayan Bay, Batangas Province, Luzon, 
Philippines, 13.74833°N, 120.75583°E, 29 May 2011, Hearst Expedition Deep Sea Team. 
Paratypes: CASIZ 192086, ST HEPD 05, dissected, beam trawl in fine mud, 459^96 m depth, 
western end of Verde Island Passage, Balayan Bay, Batangas Province, Luzon, Philippines, 
13.74833°N, 120.75583°E, 29 May 2011, Hearst Expedition Deep Sea Team. CASIZ 192087, one 
specimen, partially dissected, ST HEPD 19, beam trawl in beam ti'awl in muddy sand with pebbles, 
541-636 m depth, western end of Verde Island Passage, southeast end of Golo Island, Batangas 
Province, Luzon, Philippines, 13.5895°N, 120.4155°E, 1 June 2011, Hearst Expedition Deep Sea 
Team. 
Geographical Distribution. — Known only from the Verde Island Passage, southern 
Luzon, Philippines. 
Etymology. — The name ''acuticauda'" refers to the long tapering posterior end of the body 
of this species. 
Natural History.— This species is in mud and sandy mud in 459-636 m. 
Description. — External morphology’. The living animals (Figs. 1 A, B) are up to 65 mm in 
length and 20 mm wide. The general body color of the living animal is uniformly white with yel¬ 
lowish pigment on the anterior end of the head and in the mantle cavity on the ventral side. The 
cephalic sliield is shorter than the posterior shield and is slightly indented posteriorly. The parapo- 
dia are short, not reaching the cephalic shield, leaving the anterior and posterior shields visible 
(Fig. 2A). The posterior end of the posterior shield tapers to an acutely pointed posterior terminal. 
The gill is simply plicate consisting of 12 primary folds and is situated ventrally on the right 
posterior end of the animal. 
Shell (Fig. 2B): The shell is approximately 15 mm long and is relatively thickly calcified and 
wide. It occupies the majority of the posterior shield. No obvious sculpture is visible on the surface 
of the shell. The right posterior extreme of the shell has an elongate extension. 
Digestive system (Figs. 3A-B): The buccal mass is relatively large, occupying the anterior half 
of the anterior shield. The buccal bulb has a relatively large radula. The radular formula in one 
paratype specimen (CASIZ 192086) is 16 x 2.1.0.1.2. (Fig. 2C). The inner lateral teeth are large 
