2o8 Field Columbian Museum — Zoology, Vol. VII. 



orbital very convex, 2,5 in head; frontal fontanelle % as long as the 

 parietal ; snout short and blunt ; maxillary not quite equal to length 

 of eye; diameter of eye 3.5 in head; second suborbital leaving a 

 naked space equal to ^ its own width ; premaxillary with four teeth 

 in each series ; 'maxillary with 3 teeth ; dentary with four large grad- 

 uated teeth in front and several smaller ones similar to the last of 

 the four larger on the sides; gill-rakers short, about 6 + 11; dorsal 

 a little nearer snout than caudal, its height about \ in the length; 

 caudal about equal to length of head ; origin of anal below the tip of 

 the last dorsal ray; ventrals below the second scale in front of dor- 

 sal, reaching a little more than half way to anal; pectorals reaching 

 Yt, to ventrals; scales thin, cycloid, rather irregularly placed on the 

 belly; no interpolated scales on the sides; an exceedingly low anal 

 sheath; caudal naked; a very short and broad axillary scale; lat- 

 eral line but little decurved. 



Color silvery, an obscure vertical humeral spot; a plumbeous 

 lateral band; a caudal spot; middle caudal rays dark. 



Named for Mr. C. T. Regan of the British Museum. 



One specimen, the type. Collected by Dr. A. Alfaro. 



Cyprinodon dearborn! sp. nov. 



Type No. 6484, F. M. N. H.; length, 44 mm.; Willemstad, Cur- 

 acao, Dutch We§t Indies. 



Head 2.7 to 2.9; depth 2.1 to 2.5; D. 10; A. 10; scales 12-24. 



Body robust; dorsal region elevated; head large; interorbital 

 flat, 2.6 to 2.8 in head; snout 3.0 to 3.3; diameter of eye 3.2 to 3.4; 

 lower jaw stronger and longer than the upper; teeth tricuspid; dor- 

 sal fin inserted slightly behind ventrals, its distance from snout 1.7 

 to 1.8 in body; pectorals 1.3 to 1.5 in head; ventrals 2.8 to 2.9; 

 caudal peduncle 1.5 to 1.7 in males to 2.0 in females; humeral scale 

 enlarged. 



Color, dark olive to nearly black; males plain, the fins, except 

 dorsal, tipped with black; females variegated with darker with ten- 

 dency to form bars ; a narrow dark bar at base of caudal rays ; dorsal 

 and anal with black ocellus on middle of last rays; none of the fins 

 tipped with black. This fish resembles Cyprinus riverendi Poey, from 

 which it differs in having a larger head, more slender body, and darker 

 coloration. It is also a smaller fish. 



Willemstad, Curacao, Dutch West Indies (gcJ*), 36 to 44 mm. and 

 (49 ), 34 to 38 mm. 



Collected by Dr. N. Dearborn, for whom the species is named. 



