Calliclava McLean, 1971

Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, Zootaxa 4090 (1), pp. 1-363 : 47

Genus Calliclava McLean, 1971

Type species: Cymatosyrinx palmeri Dall, 1919 , by original designation (Recent, beach at the head of the Gulf, Gulf of California).

Diagnosis. According to McLean (1971: 117), shell small to medium sized, surface glossy, body whorl short in comparison with the spire. Protoconch large, of two carinate whorls. Axials from suture-to-suture, but weak in sulcus. Spirals of incised grooves. Anal sinus on shoulder deep, U-shaped, bordered by a curved parietal callus. Outer lip nearly straight with a moderately deep stromboid notch; a varix is present ¼-turn from the edge of the lip. Anterior canal short, notched.

Key characteristics. The combination of the following characteristics is diagnostic of Calliclava and separates the genus from all other TWA Drilliidae :

1. Axial ribs numerous, extend from suture-to-suture, depressed and recurved in the sulcus, and run to anterior fasciole on body whorl; ribs overridden by spiral grooves that are shallow on crests, deeper in intercostal spaces;

2. Protoconch of about 2–2¼ smooth, translucent, keeled whorls; and

3. Varix broad and hump-like positioned about ⅓-turn from the edge of the outer lip; marked with a dark color patch.

Nomenclatural notes. This genus was erected by McLean for species that otherwise resembled Clathrodrillia , but differ in possessing a protoconch that is carinate from the tip of the first whorl, and a radula with a compressed, not elongate, lateral tooth. Dall erected separate genera, Elaeocyma Dall, 1918 ; and Kylix Dall, 1919 for eastern Pacific drilliids with partially keeled protoconchs.

TWA species of Calliclava are similar in appearance to Calliclava palmeri (Dall, 1919) , the type of the genus. Another eastern Pacific species, Calliclava subtilis McLean & Poorman, 1971 , is also similar. Ten species of Calliclava are listed in the on-line database, World Registry of Marine Species as of the date of this research, all from the eastern Pacific (WoRMS, 2016). The Calliclava herein are the first to be described from the TWA.

Similar genera. The genus Calliclava is most easily distinguished by its fully carinate protoconch. Although otherwise close in appearance, only the second protoconch whorl of Elaeocyma Dall, 1918 is carinate. Other drilliid genera with carinate protoconchs include Imaclava , and Kylix , but none have a carinate first whorl.

Clathrodrillia Dall, 1918 differs in possessing a smooth, not carinate protoconch. Agladrillia Woodring, 1928 differs in possessing only a carinate second protoconch whorl, a varix positioned ½-turn from the edge of the outer lip, and axials obsolete from the varix to the outer lip. Agladrillia also has a more acutely “pinched” anterior, as opposed to the tapered one of Calliclava .

Distribution. Calliclava is only known from off the northern coast of South America.