Conus busuegoi         (Shuto, 1969)

 

 

Mαterial.

Holotype: GK-L 6431 and paratypes GK-L 6429, 6430 and 6559.

GK-L 6429 to 6431 came from loc.  SKGS-73 and GK-L 6559 from SKGS-71.

 

Measurement

 

specimen

H

Bd

Ap

D

Bd/H

Ap/H

D/H

GK-L

 

(mm)

 

(mm)

 

(mm)

 

(mm)

 

(%)

 

 

 

 

6429

 

18.00

 

13.95

 

13.10

 

6.30

 

77.4

 

72.8

 

35.0

6431

 

29.45

 

24.00

 

—

 

10.20

 

81.4

 

—

 

34.7

6559

 

21.45

 

16.80

 

15.75

 

7.20

 

78.4

 

73.5

 

33.7

specimen GK-L

 

<A

<P

protoconch

teleoconch

 

(degrees)

H

D

numb.

6429

 

44.3

 

56.4

 

1.04

 

0.94

 

2.5

 

6.4

 

6431

6559

 

40.2

36.9

 

67.7 56.5

 

1.00 1.08

 

0.88

0.90

 

2.4 2.4

 

7.2

7.4

 

 

 

Diagnosis.

The shell is moderately small, slender, and asymmetrically bi-conical with three to four times longer basal cone than the spire. The spire is moderately extraconical with acutely elevated early whorls. The protoconch is low conical and paucispiral consisting of less than two and a half volutions, which are separated one another by the deep suture. The first volution is very small, smooth, remarkably oblique, and bluntly rounded; the remainder volutions are regularly rounded, moderately convex, and also smooth except for the last one-eighth volution, which is provided with about two to three distinct and rather wide, almost vertical axial riblets. The termination of the protoconch is not sharply defined, but the appearance of the peripheral angulation with gemmules and distinct infrasutural spiral sulcus indicates the beginning of the teleoconch. The teleoeonch of the largest specimen consists of 7.2 whorls. The blunt peri­pheral angulation is situated at the middle of the whorl, provided with axially and somewhat obliquely elongated blunt granules, and emarginated by the wide and sharp sulcus above and the shallow groove below on the first whorl. The subsutural part and the sulcus are ornamented by the coarse and raised growth lines. On the course of the growth stages the peripheral angulation gradually moves its position anteriorly and consequently it is at lower one-fourth on the penultimate whorl. Keeping pace with the change of the position, the granules are confined to the lower part of the angulation and finally they become very weak or obsolete on the latest whorls. On the second or third whorl another very weak spiral groove is intercalated between the infrasutural sulcus and the peripheral band and gradually becomes distinct and sharp. The basal surface of the body whorl is ornamented with about 32 to 33 narrow spiral sulcae which is sharply defined with the steep wall and flat bottom crossed by the raised growth lines and separated one another by the flat-topped lirae. The spiral sulcae are regularly spaced and narrower at the upper part than at the lower. On the full grown specimen a few secondary spiral grooves are irregularly intercalated at the middle and lower parts. The aperture is very narrow and long with quite parallel lips.

 

Comparison.

The present specimens are characterized by the slender outline, uni-sulcate concave shoulder, gemmulated peripheral angulation of the early whorls, and regularly spaced distinc spiral sulcae on the lateral surface of the body whorl. With these diagnostic features they are closely allied to Conus longurionis KIENER, especially to MARTIN’s fossil specimens from Indonesian Pliocene. They are, however, distinguished from each other in several points.

The peripheral granules are still discernible on the fifth and sixth whorls on the present specimens, while they disappear on the third whorl on the Indonesian specimens. The spire of the latter is less extraconical than that of the former.

In these respects the Indonesian specimens are close to the living Conus longurionis from South China Sea. The decisive difference between the present specimens and Conus longurionis is examplified in the feature of the protoconch; the protoconch of the present specimens is bluntly conical and paucispiral consisting of less than two and a half volutions, while that of longurionis is high conical, polygyrate, and weakly convex at the sides. On these basis the present specimens are reasonably separated from C. longurionis at the specific level.

The general profile and the uni-sulcate shoulder of the present specimens are similar to those of C. palabuanensis MARTIN (1895, p.16. Taf.2. f.26), but the latter has the flat-sided spire-whorls, which are devoid of the  peripheral angulation and gemmules.

 

Conus sondeianus MARTIN(1895. p.14. Taf.1. fs.16 and 17) is also similar to the present specimens in the general profile of the shell and the gemmulated whorls, but the sulcae of the shoulder on the former species are several instead of only one of the latter.

 

Horizon.

Santa Barbara Silt and the upper part of the Ulian Formation.

Localities SKGS-71and 73.

 

 

 

Conolithus busuegoi

Pl. 24   Figs. 18-19  and 22-24

 

 

 

 

Bibliografia

 

 

·         (1) – Shuto Tsugio, (1969) “Neogene Gastropods from Panay Island, the Philippines”. Memoirs of the Faculty of Science, Kyushu Imperial University, ser. D. vol. 19 (1 ) pag. 215

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