378 
THE CORAL TRIANGLE: HEARST BIODIVERSITY EXPEDITION 
microscopic network on the gizzard plates, although a fibrous network is evident (Fig. 12C). The 
gizzard namows posteriorly and enters the digestive gland. The intestine emerges from the right 
side of the digestive gland and terminates near the posterior end of the body near the base of the 
gill. 
Central Nervous System (Fig. 13C): The circumesophageal nerve ring consists of paired cere¬ 
bral, pedal and pleural ganglia and a single supraintestinal ganglion immediately posterior to the 
right pleural ganglion. The cerebral and pedal commissures are both somewhat elongate with well- 
separated respective ganglia. On the ventral side of the buccal mass near the entrance of the esoph¬ 
agus are the buccal ganglia, which are immediately adjacent to each other. From the posterior end 
of the anterior nerve ring the right branch of the visceral loop the osphradial nerve extends poste¬ 
riorly from the supraintestinal ganglion. The two lateral branches of the visceral loop join posteri¬ 
orly at the posterior ganglia. The left visceral loop enters the subintestinal ganglion, while the right 
lateral nerve enters the visceral ganglion. The visceral ganglion is larger than the subintestinal gan¬ 
glion. From the visceral ganglion is the genital ganglion which bifurcates into a paired gential 
nerves. 
Reproductive System (Figs. 12E-F, 13D-E): The aiTangement of reproductive organs is essen¬ 
tially monaulic (Fig. 13D) (as discussed by Gosliner 1994), but with a single branch of the her¬ 
maphroditic duct to the albumen and membrane glands. From the large ovotestis, which is inter¬ 
mingled with the digestive gland, emerges the wide, convoluted ampulla. The ampulla narrows 
considerably. After the hermaphroditic duct crosses over the receptaculum seminis, it widens and 
curves around the distal surface of the pyriform receptaculum. The duct completes a circle around 
the receptaculum and branches to the albumen and membrane glands and also receives the duct of 
the receptaculum. The duet then enters the massive, highly muscularized genital atrium near the 
wide duct of the bursa copulatrix. The large, ovoid bursa has a thin wall. The entire bursa duct is 
wide and short and curved. The albumen and membrane glands are small. The larger mucous gland 
is bilobed with a large primal^ lobe and small secondary one. There are no secondaiy bursae evi¬ 
dent in the specimen dissected. From the genital atrium the open, ciliated sperm groove leads to the 
cephalic penis. The penis (Fig. 12E-F, 13E) consists of a broad penial sac and an elongate, highly 
branched, posteriorly directed prostate gland and associated ducts that characterize members of the 
Phil in e aperta clade. There is a large, wide retractor muscle situated on the ventral surface of the 
penis. Within the penial sac a large bulbous penial papilla with a curved apex is present. The entire 
surface of the papilla is ornamented with conical papillae (Figs. 12E-F, 13E). 
Remarks. —Morphologically, Philine multipapillata is similar to other members of the Phi- 
line aperta clade in that it has gizzard plates with pores and a penial complex with a highly convo¬ 
luted and branched prostate. It is the only member of this species complex with a penial papilla 
ornamented with numerous conical papillae. Like P. habei, P puka, P rubra, and P. verdensis, it 
has relatively large pores on the gizzard plates. It is similar to P. puka, P verdensis, and P. rubra, 
in that the pores on the gizzard plates are more or less the same size, whereas in P. habei, they are 
markedly unequal. The microstructure of the gizzard plates also differs in the five species. In 
P. puka, there is a distinct honey-combed pattern present, whereas in P. habei andP. multipapilla¬ 
ta (present study) there is some organization of a honeycomb pattern, but it is not as highly organ¬ 
ized as in P, puka. In P. verdensis, there is no indication of any organized micro structural pattern. 
The microstructure remains unknown for P. rubra. All of these species have only inner lateral radu- 
lar teeth and lack outer laterals. The denticles on the inner laterals of P. verdensis are more uneven 
than those of P. muhipapillata, P puka, and P. rubra. Philine multipapillata has more denticles on 
the inner lateral teeth (56) than do P puka (39-44) orP verdensis (45). The number of denticles 
was not described for P rubra, but Bergh’s figure seems to indicate there are fewer denticles than 
