New Species of Goliath Beetles

 A. H. Verrill—New Species of Dynastes.

Art. XXVIII.— Descriptions of two remarkable new species of Goliath Beetles (Dynastes) from Dominica Island, Antilles—Brief Contributions to Zoology from the Museum of Yale University, No, LXVI; by A. Hyatt Verrill. From The American Journal of Science, 1906.
Researched by Dennis Lien; digitized by Doug Frizzle, May 2012.

Dynastes tricornis sp. nov.

Male.—Elytra, thorax, and head polished, deep purplish black with no hair except along the edges of the segments, where the hairs are short, sparse, and rusty or ferruginous red; ventral surface highly polished, deep brownish black with very few sparsely distributed reddish hairs along the edges of the segments. Legs stout, black, and smooth, except along the tibiae of the anterior pair, which are deeply but minutely pitted; tarsi and tibiae edged with fine reddish hairs; processes of tibiae very similar in form to those of D. Hercules. Dorsal outline of elytra broad, obtuse, and slightly compressed laterally at a point about one-third the distance between the anterior and posterior extremities.

Thorax shield-shaped in a dorsal view; concave in a lateral view and bearing three slender, smooth, curved, processes or "horns.'' The three horns are arranged in a triangle with the two posterior ones forming its base and curving forward and inward toward the third process, which forms the apex of the triangle; the anterior processes rounded below and flattened above, somewhat thickened near the center and curved semi-circularly upwards at the outer end. No hairs on any of the thoracic processes.

Head minutely pitted and without appendages of any sort, except a small, slightly raised, transverse ridge between the eyes. Lateral posterior edges of the thorax below appendages and upper surface of anterior appendage minutely pitted.

Length from anterior extremity to tip of abdomen (exclusive of thoracic process), 1.45 inches; width of thorax at posterior segment, 0.60; width of thorax at widest point (across two posterior processes), 0.70; width of thorax at anterior segment, 0.25; width of elytra at widest point, 0.85; length of two posterior thoracic processes, 0.35; length of single anterior process, 0.45.

Habitat.—Highest mountain slopes of the island of Dominica.

Several specimens. Female unknown.

As will be seen by the foregoing description, this new Dynastes is very distinct from any other species of the genus. Its small size, three thoracic and no occipital appendages, as well as its polished and uniformly colored surface are characters which serve to identify it at a glance.

In the arrangement of thoracic horns it resembles D. Neptunus from South America, but from this species it differs very materially, it appears to be very rare in Dominica, for during two years collecting in the island I have procured but few specimens, and it is unknown to most of the natives, who, as a rule, are fairly familiar with the fauna of the island.

Dynastes Lagati sp. nov. Figure 1.

Male.—Much smaller than either Dynastes Hercules or Vulcan and averaging scarcely if any larger than Dynastes tricornis.

Elytra brownish olive, with a bright metallic luster in living specimens, sparsely and irregularly spotted with circular markings of deep brown, most numerous near the posterior extremity and lateral and anterior edges. Thorax, head, abdomen, legs, ventral surface, edges of elytra and a broad band across anterior portion of elytra, rich chestnut-brown. Thorax with a short, cylindrical, slightly curved process.

Head with a stout, short, crescent-shaped process. Thoracic "horn" with a minute, scarcely perceptible process on either side at base. Occipital "horn" without protuberance of any sort except a very minute notch or tooth on the dorsal surface near the base.

Entire dorsal surface thickly and conspicuously pitted and everywhere covered with short, yellowish brown hair which becomes longer and conspicuous around the base of the occipital process, posterior portion of thorax, and along the median line of elytra. Ventral surface of thoracic process covered with thick, velvety, golden-yellow hair. Ventral surface of head, thorax, and abdomen finely but thickly pitted, and with scarcely any hair except along the edges of segments and posterior extremity of abdomen; the latter with a long thick fringe of silky golden hair,

Females—Scarcely distinguishable from female of D. Hercules, except by the much smaller size and abundant hair which completely covers the dorsal surface.

Length, exclusive of thoracic and occipital processes, 2.00 to 2.25 inches length of thoracic process, 0.45 to 0.60; length of occipital process, 0.20 to 0.25 width of thorax at posterior segment, 0.50 to 0.85.

Habitat.—Interior mountain ranges of Dominica I., from 2000 to 4000 feet above sea level. Several specimens.

To make this notice more complete, the description of a third rare species is here reproduced. It was originally described in a brochure published by A. H. Verrill at Rosseau, Dominica, April, 1905.*

* Description of a new species of Dynastes (Hercides Beetle) from, Dominica. By A. Hyatt Verrill.

Dynastes vulcan A. H. Verrill. Figure 2, b.

Male.—Much smaller and with much shorter and more slender thoracic and occipital processes than even the smallest and most undeveloped specimens of Dynastes Hercules.

The thoracic "horn" is much more curved and has the two lateral projections much nearer base than in D. Hercules. Occipital horn slender near base but wide vertically from a point near middle to near the anterior end; compressed laterally, broad in profile, but slender when viewed anteriorly, in marked contrast to the occipital appendage of D. Hercules, in which species the occipital "horn” is fully as wide anteriorly as laterally, and nearly circular in section.

Protuberances on occipital appendage three in number and of almost equal size and equally spaced between anterior extremity and middle of the "horn." No indication of a bifurcated tip to the occipital appendage, as is usually the case with D. Hercules. Anterior profile outline of occipital process almost straight, not convex as in D. Hercules. Thorax broader, more depressed, and less conical in dorsal outline than in Hercules. Elytra broader, more obtuse posteriorly, and more convex in profile than in D. Hercules. Color of elytra uniform, dark, sooty-brown, occasionally with indications of circular or lunate markings of a lighter, more yellowish shade. Lower parts lighter and more brownish than in Hercules, with more abundant and lighter colored hair; especially on ventral surface of the head and thorax. Dorsal portion of thorax, especially posteriorly, much rougher and more deeply pitted than in D. Hercules.

Length, from anterior extremity to tip of abdomen, exclusive of thoracic appendage, 2.60 to 2.65 inches; dorsal length of thoracic appendage, 1.40 to 1.50; anterior length of occipital appendage, 1.06 to 1.10; width of thorax at posterior segment, 1.15 to 1.20 inches.

Habitat.—Windward or Atlantic slopes of Dominica. Three specimens. Female unknown.