Geophis hoffmanni, (PETERS, 1859)

Savage, Jay M. & Watling, James I., 2008, Not so rare snakes: a revision of the Geophis sieboldi group (Colubridae: Dipsadinae) in lower Central America and Colombia, Zoological Journal of the Linnean Society 153 (3), pp. 561-599 : 588-589

GEOPHIS HOFFMANNI ( PETERS, 1859) ( FIG. 1D )

Colobognathus hoffmanni Peters, 1859: 276 , fig. 2 [Type locality: Costa Rica; Lectotype: ZMB 4003, an adult female by action of Downs (1967)].

Elapoides hoffmanni, Jan, 1862: 22 .

Geophis hoffmanni, Bocourt, 1883 in A. Duméril, Bocourt & Mocquard, 1883: 529, pl. 31, figs 8, 8a–c; Downs, 1967: 155, fig. 19; Savage, 2002: 603, pls 371–72; Myers, 2003: 40; Solórzano, 2004: 284, fig. 79. Rhabdosoma bicolor, Cope, 1885: 529 (in part).

Geophis chalybaea, Günther, 1893: 87 (in part).

Catastoma hoffmanni , do Amaral, 1929: 192.

Geophis bartholomewi, Brattstrom & Howell, 1954: 120 , fig. 1 (Type locality: Honduras: El Paraíso: Los Arenales, 380 m = Nicaragua: Nueva Segovia: Arenal of original description; Holotype: CAS 91202, an adult female).

Geophis acutirostris, Taylor, 1954: 691 , fig. 3 (Type Locality: Costa Rica: Cartago: Oreomuno: Cot , 1817 m; Holotype: KU 34760 ).

Diagnostics: One of the most distinctive species of Geophis differing from all others in the following combination of characters: (1) usually five supralabials, rarely four; (2) one supralabial lies posterior to orbit; (3) no anterior or posterior temporal but postsupralabials present; (4) very large last supralabial in broad contact with the parietal; (5) two large postsupralabials posterior to last supralabial and upper in contact with the parietal; (6) dorsal scale in 15–15–15 rows; (7) dorsal and caudal scales smooth, except for a few above vent; (8) anterior tip of maxilla pointed, toothless; posterior end of maxilla depressed and curving ventrad; (9) ventrals 117–124.5– 130 in males (N = 33), 122–131.2– 135 in females (N = 42); subcaudals 28–32.1.9– 37 in males (N = 31), 23–27.9– 32 in females (N = 38); ventral plus subcaudals 147–168 (N = 60); ventrals 128, subcaudals 27 in one juvenile of indeterminate sex; (10) upper surfaces of body and tail black; venter immaculate in juveniles, banded in larger snakes; light head band present in most juveniles, obliterated in larger specimens.

Variation: This summary includes data on this common species from Downs’s (1967) account: the largest male is 197 mm in standard length with a tail length of 36 mm (15.5% of total length); total length 233 mm. The largest female is 260 mm in standard length with a tail length of 40 mm (13.3% of total length); total length 300 mm.

The loreal is excluded from the orbit by contact between the prefrontal and third supralabial in seven snakes; the shape of the supralabials indicates that this condition involves fusion of the supralabial with the posterior portion of the loreal. Preoculars 0–0. Postoculars 0–0 (N = 2), 0–1 (N = 2), 1–1 (N = 70), 1–2 (N = 4); postocular reduced and separated from supraocular by an extension of the parietal (N = 10). In one snake a narrow extension of the upper postsupralabial separates the fifth supralabial from contact with the parietal ( Savage, 2002). Supralabials 4–4 (N = 1), 4–5 (N = 1), 5–5 (N = 70). The foursupralabial condition results from a fusion of supralabials 3 and 4; supralabials 3 and 4 usually border the orbit but only the third supralabial when only four supralabials are present. Infralabials 5–6 (N = 3), 6–6 (N = 74), 6–7 (N = 1); usually four (N = 75) and rarely two or five infralabials contact the genials. See Appendix 4 for notes on the type series.

Hemipenes: Based on a retracted hemipenis ( Downs, 1967). Organ slightly bilobed. Pedicel covered with spicules and 2–3 medium spines in the distal region. Truncus bears numerous spines. Capitulum covered with spinulate calyces.

Remarks: Myers (2003) extended the known range of this species in Panama from Downs’ easternmost record at Coclé: Valle de Antón to two sites east of the Panama Canal, Panamá: Madden Forest, c. 100 m (AMNH 113561) and Panamá: Piedras-Pacora Ridge: Cerro La Victoria, 670 m (FMNH 152047). He also recorded G. hoffmanni (AMNH 108373) for the first time from Colombia (no specific locality). Additional Panama records include two females (CHP 605 and 4343) from Panamá: Parque Nacional de Altos Campana and one juvenile (FMNH 216258) from Panama: around Panama City. All three have 15–15–15 rows of dorsal scales, supralabials 5–5, with three and four bordering the orbit, no temporals and 6–6 infralabials (four bordering the genials). CHP 605 is 183 mm in standard length with a tail length of 24 mm (11.6% of total length) and has 133 ventrals, 26 subcaudals and ventrals plus subcaudals number 159. CHP 3243 is 156 mm in standard length with a tail length of 19 mm (11.0% of total length); total length 175 mm; 127 ventrals, 23 subcaudals and the ventrals plus subcaudals equal 150. FMNH 216258 is 146 mm in standard length with a tail length of 20 mm (12.0% of total length); total length 166 mm; ventrals 128, subcaudals 27 and ventrals plus subcaudals equal 155.

Downs (1967) and Myers (2003) both pointed out that the reduction to five supralabials in this species is not due to fusion of two supralabials. Rather, it is caused by a shortening of the gape and jaw ( Fig. 1D ). The upper postsupralabial is clearly homologous to the posterior temporal and the lower postsupralabial to supralabial 6 of other species treated here. The postinfralabial seems to be homologous to infralabial 7 or 7 fused with jubal IV. These features indicate that the shortening of the jaws was from the posterior end.

Distribution: Found in areas that currently or formerly were covered by a variety of forest vegetation, including tropical lowland moist and wet forests, tropical premontane moist and wet forests and rain-

Figures

Figure 1. Lateral head scalation in Geophis: A, pattern typical of G. zeledoni; B, pattern typical of G. brachycephalus complex; C, variant pattern; D, pattern typical of G. hoffmanni. PT, posterior temporal; U, upper postsupralabial; L, lower postsupralabial; PI, postinfralabial; number of supralabials and infralabials indicated by Arabic numerals; number of jubals indicated by Roman numerals.