66 University of California Publications in Zoology 



taxa whose organisms reach different sizes. As stated above, Conolophus and 

 Dipsosaurus generally lack pterygoid teeth, although I have observed up to two and four on 

 a single pterygoid in these genera, respectively. Amblyrhynchus, Brachylophus, and 

 Sauromalus generally have fewer than 10 pterygoid teeth and always have less than 15 (the 

 maximum numbers that I have observed are seven, 11, and 12, respectively). Because of 

 the wide range in body size of their included species, Ctenosaura and Cyclura exhibit a 

 wide range in pterygoid tooth number. Members of the large species of Ctenosaura (C. 

 acanthura, C. pectinata, C. similis) usually have over 20 pterygoid teeth and sometimes 

 exceed 30. Small species such as C. clarki, C. defensor, C. palearis, and C. 

 quinquecarinata probably never have as many as 20 such teeth. Cyclura exhibits a range in 

 the number of pterygoid teeth similar to that of Ctenosaura, but I have few adequate 

 ontogenetic series for species in the former genus. The most teeth that I have seen on a 

 single pterygoid in Cyclura is 26 in a specimen of C. pingius that had not yet undergone the 

 fusion of braincase elements indicative of the attainment of maximum size. If allometric 

 trends in this species are similar to those in Iguana and Ctenosaura, larger organisms 

 probably have upwards of 30 such teeth. Iguana is characterized by a high pterygoid tooth 

 number. Large /. delicatissima have a maximum of at least 30 pterygoid teeth, while the 

 number exceeds 60 in /. iguana. I did not use variation in pterygoid tooth number as a 

 separate systematic character, though some of this variation is incorporated in the characters 

 that were used. 



Scleral Ossicles (Fig. 32). The scleral ossicles are thin wafers of bone that overlap one 

 another in such a way that they form a ring within the sclera on the corneal side of the eye. 

 The number of scleral ossicles and their pattern of overlap is fairly constant within 

 squamate species, and a standard terminology has been developed to describe and number 

 individual ossicles for purposes of comparison (Gugg, 1939; Underwood, 1970). Most 

 Iguanidae characteristically possess 14 scleral ossicles per eye, with the following patterns 

 of overlap: ossicles 1, 6, and 8 overlap both immediately adjacent ossicles; ossicles 4, 7, 

 and 10 are overlapped by both immediately adjacent ossicles; and the remainder are 

 overlapped by one neighboring ossicle while overlapping the other (Underwood, 1970; de 

 Queiroz, 1982). In a previous study (de Queiroz, 1982), I reported this pattern for all 

 iguanine genera. I have now examined the following additional species and report the same 

 ossicle configuration: Brachylophus vitiensis (one eye from one specimen examined); 

 Ctenosaura bakeri (Roatan Island; 2, 1); C. clarki (4, 4); C. defensor (1, 1); C. palearis (1, 

 1); C. quinquecarinata (1, 1); C. similis (8, 5); Cyclura carinata (4, 2); and C. rileyi (2, 1). 

 Additional material of Amblyrhynchus (2, 1) also exhibits this pattern, supporting my 

 previous suggestion that two specimens with fewer than 14 ossicles are anomalous. 



Hyoid Apparatus (Fig. 33). The hyoid apparatus lies within the tissue between the 

 mandibles, where it serves as the skeletal framework for the tongue and throat muscles. 

 This delicate structure is often lost or partially destroyed in dry skeletal preparations. In 

 iguanines, the hyoid apparatus consists of a median, anteriorly directed hypohyal (lingual 

 process); the body of the hyoid, which is also a median element and is continuous with the 

 hypohyal; and portions of three pairs of visceral arches. The hyoid arch is the most lateral 



