189S.] HTOID OF ALTTES OBSTETEICANS. 5 



superficial bone (v) which is related to the hyoglossus muscle in 

 the same way as the H-shaped splint-bone of Pelochjtes. Tbe 

 antero-lateral or alary processes (pa^ ^^'^^ ^^^^ postero-lateral 

 processes (jpjjl) are feebly developed, but they are hardly so 

 reduced in size as to justify the statement by Stannius (10. p. 65, 

 footnote) : " bei Alytes ist, statt zweier Seitenfortsiitze, jederseits 

 eine breite Platte vorhanden." 



Of the published figures of the hyoid skeleton of Alytes, that by 

 Parker (7. pi. 24, fig. 4) is the most reliable. This author regards 

 the splint-bone as an ectosteal basibranchial (p. 134), and describes 

 (p. 133) the hyoidean cornua as having small hypohyal lobes 

 (= proc. ant. 9. p. 589), lobes which I find to be altogether 

 wanting in the Discoglossid genera Alytes, Discoglossus, and 

 Bombiiiator. The much earlier figure of Heule's (5. pi. 2, fig. 24), 

 reproduced by Hoffmann in the ' Klassen und Ordnungen des 

 Thierreichs ' (6. pi. 46, fig. 24), is not much inferior to that of 

 Parker's; but the one given by Duges (2. pi. 3, fig. 20) is 

 decidedly poor. Only the proximal ends of the hyoidean cornua 

 are shown, and the lateral parts of the basal plate are represented 

 in the figure, and described in the text (2. p. 56), as ossified in 

 the same manner as in Bomhinator. Cope (1. pi. 76, fig. 3) 

 endeavoured to compromise matters by combining the figures of 

 Duges and Parker, from which fact it is evident that he had 

 never seen the hyoid of Alytes, or he would have rejected ])iiges'8 

 figure entirely. The statement by Cope (1. p. 234) that " some- 

 times the third ceratobranchial is ossified, as in Alytes (pi. 76, 

 fig. 2)," involves a confusion of Alytes with Bomhinator, for the 

 figure referred to is that of the latter genus. The statement 

 would, however, in neither case be correct. 



Stage 1. Specimen measurincj from snout to root of tail 20 mm. 

 Lenrjih of tail 40 m»i. Length of hind limb 2 mm. (Plate II. 

 fig. 1.) 



The ceratohyals (c7i) are broad and flat at their mesial ends, 

 while their lateral extremities bear each a convex surface for 

 articulation with the palatoquadrate cartilage and a terminal 

 process for muscular attachment. They are not in contact with 

 one another in the median line, but between them occur first an 

 elliptical cartilage, the anterior copula (ca), then a space, then a 

 fibrous mass, the " pars reuniens " (pr), and finally a posterior 

 copula (cp) of larger size than the first. The postero-internal 

 edges of the ceratohyals abut on the hypobranchial cartilages 

 (hb). The anterior copula (" erste Copula " of Gaupp, 3. pp. 411 

 and 41 2, to whom the discovery of this cartilage is due ^) is 

 elliptical in shape, the long axis of the ellipse being disposed at 



1 Grotte (4. pi. 18, fig. 332) gives a figure of the larval hyobranchial skpleton 

 of Bombinator showing three axial structures which probably represent the 

 first and second copula, with the pars reuniens between. The relations, 

 however, are not clearly indicated, and no special description is given of these 

 parts in the test, so that the credit of the discovery of an anterior copula in 

 Anuran tadpoles must be accorded to Gaupp. 



