97 



Ground coloin- (in spirits) brown, the darkness of llie 

 tint being produced by short oblong specks. The body is 

 crossed by about sixteen pale rings, occupying nearly as 

 much space as the dark colour. The rings are not all 

 complete. 



Length 28 inches. To anus 18 inches. To gill-open- 

 ing 4.3 inches. 



This is the description of the British Museum specimen 

 preserved in spirits. The dried one figured in the Zoology 

 of the Sulphur has rather wider dental plates, owing pro- 

 bably to its gi-eater age. It measured 48^^ inches. 



Hab. Gulf of Mexico ? Sea of China"? 



Ophisurus 



I have had no opportunity of examining the skeletons of 

 the Ophisuri, nor of comparing the viscera of the different 

 groups, and cannot therefore enumerate the principal cha- 

 racteristics of the genus, as I did with the Miircena: in 

 page 78, but I have given short descriptions of the exter- 

 nal characters of all the species that have come under my 

 notice. 



M. Valenciennes characterises the genus by the elon- 

 gated cylindrical body tapering towards the tail, clothed 

 with naked skin, destitute of scales ; the moderate gape ; 

 compressed knife-like [denies cultrati) teeth, or rounded 

 obtuse ones ; the dorsal reaching from the occiput to the 

 naked conical point of the tail ; the anal like to it, but 

 shorter ; the pectoral fins more or less flabellate ; the gill- 

 rays thirty in number. Cuvier divides the species into two 

 groups ; one having pectorals of the ordinary size, and 

 sharp and trenchant teeth ; the other having pectorals ex- 

 ceedingly small, so much so as to have been overlooked by 

 some observers altogether, and obtuse teeth. The disco- 

 very of additional species since the publication of the 

 Reyne Animal has rendered this subdivision less exact, for 

 the Oph. cancrivorns presents the combination of pretty 

 large pectorals with obtuse teeth ; and we shall also 

 describe species that have almost rudimentary pectorals 

 with acute teeth. In fact, the gradation from acute or 

 acicular teeth to small rounded grinding ones is almost 

 imperceptible, and there is a similar passage from the large 

 to the minute pectorals. I have seen no species with 

 teeth so trenchant as the stiletto-pointed teeth of some of 

 the Mur(B)i<e, — certainly none meriting the designation of 

 denies cultrati. The following artificial arrangement, 

 founded on the dentition and size of the pectorals, may be 

 useful to the student in the discrimination of species. 



A. Teeth short, conic, more or less blunt. 



a. Pectorals comparatiiely large. 



Teeth triserial or pluriserial on the several bones. 

 O. cancrivorus ; sinensis; semicinctus ; boro. 



b. Pectorals small or rudimentary. 



1. Vomerine teeth tri- or pluriserial ; palatine and man- 

 dibular teeth biserial. 

 O. breviceps ; pardalis. 



2. Vomerine teeth biserial ; palatine teeth uniserial ; 

 mandibular teeth uniserial or sub-biserial. 

 O.fasciatus ; colubrinus. 



B. Teeth acute, conico-subulate, subulate or acicular. 



a. Pectorals small atid delicate, moderate sized 



or rather large. 



1. Vomerine teeth triserial ; palatine and mandibular 



teeth biserial. 

 O. pallens. 



2. Vomerine teeth biserial ; palatine and mandibular 



teeth biserial. 

 O. hijala ; maculosus ; intertinctus. 

 .3. Vomerine teeth sub-biserial or uniserial ; palatine 

 and mandibular teeth uniserial. 

 O. .tpadiceus ; versicolor. 



4. Vomerine teeth uniserial ; palatine and mandibular 



teeth biserial 

 O. sugillatus; ocellatus ; par His ; dicellurus ; ros- 

 tellatus. 



5. Vomerine teeth uniserial ; palatine teeth uniserial ; 



mandibular teeth biserial. 

 O. compar. 



6. Vomerine teeth uniserial ; palatine teeth biserial ; 



mandibular teeth uniserial. 

 O. regius fvel ophis ? ); serpens. 



b. Pectorals minute, no vertical Jins. 

 Teeth on the several bones uniserial. 



O. vimineus. 



Obs.— Ophisurus cancrivorus, breviceps, compar and 

 parilis, have a close external resemblance, and may be 

 confounded if attention be not paid to the dentition, and 

 some other comparative characters included in the descrip- 

 tions. In like manner, there is a general similarity in the 

 markings of semicinctus, pardalis, maculosus, intertinctus 

 and sugillatus. O. harancha, pallens, spadiceus, versicolor 

 and hijala, form a small group, of a peculiar aspect, which 

 belongs to India and China. O.fasciatus and colubrinus 

 are remarkable for the length of their long, compressed 

 banded bodies ; versicolor, which is also banded, is more 

 cylindrical; and serpens and regius, agreeing in the 

 nacry lustre of their bodies, differ from one another and 

 from all the rest in the forms of their laterally expansible 

 jaws. O. vimineus differs from the other species in the ab- 

 sence of vertical fins, just as the Ichthyophis of Lesson 

 does from the Murcence. 



Ophisurus cancrivorus. Richardson. 



Plate L., figs. 6—9. 



Nasal disk circular, armed with about fifteen crowded, 

 round, rather flat-crowned teeth, of different sizes, sepa- 

 rated from the dental surface of the vomer by a mem- 

 branous line. The vomerine teeth stand about five abreast 

 throughout, but the anterior part of the dental band, being 

 composed of larger teeth, is wider. The swelling folds of 



